It is feared that terrorists could transport an improvised nuclear device up the Thames and detonate it in the heart of London. Bristol, Liverpool, Newcastle, Glasgow and Belfast are also thought to be vulnerable.

Lord West, the Security Minister, also raised the possibility of terrorists using small craft to enter ports and launch an attack similar to that in Mumbai in 2008, when more than 150 people were killed.

The Government is so concerned about the threat that it is setting up a command centre to track suspicious boats. The terrorism threat level was raised from "substantial" to "severe" in January after the failed attempt to blow up an aircraft over Detroit on Christmas Day. Three separate reviews of the country's ability to prevent a major terrorist attack were published simultaneously yesterday, before an international meeting on nuclear security in Washington next month.

Downing Street released an update to the National Security Strategy in which it stated that "the UK does face nuclear threats now" and added that there was "the possibility that nuclear weapons or nuclear material [could] fall into the hands of rogue states or terrorist groups". The International Atomic Energy Authority recorded 1,562 incidents where nuclear material was lost or stolen between 1993 and 2008, mostly in the former Soviet Union, and 65 per cent of the losses were never recovered.

The decision comes amid heightened tensions between Beijing and Washington over a range of issues, from Internet freedom to the yuan exchange rate, economic sanctions on Iran and US weapons sales to Taiwan. "Google has violated the written promise it made on entering the Chinese market," said an unnamed official from China's State Council Information Office, which helps oversee Internet rules, according to the Xinhua news agency.

"It is totally wrong in halting (censorship) filtering of its search provider," said the official. "We firmly oppose politicizing commercial issues, and express our dissatisfaction and anger at Google Inc's unreasonable accusations and practices," said the official. Google said on January 12 it would no longer censor its China-based Google.cn search portal and was also alarmed by hacking attacks from within China.

Google acted on that threat, throwing the burden on Beijing to apply its own censorship filters to keep Chinese users from seeing banned images and words when rerouted to the company's Hong Kong site, google.com.hk.

The storms are a product of worsening desertification in Inner Mongolia and other Gobi Desert regions hundreds of miles to the north and west of Beijing caused by overgrazing, deforestation, drought and urban sprawl. Strong winds pick up the loose dust and dirt, mixing them with industrial pollution.

Beijing's air quality index was set at Level 4, one grade better than the most serious Level 5 that was reached Saturday as the mixture of sand, dust and pollution blasted the capital. City meteorologists said conditions would improve, but warned the sand would linger through midweek. Record pollution levels were registered in Hong Kong, 1,240 miles (2,000 kilometers) to the south, partly due to the storms. Schools were advised to cancel outdoor activities and at least 20 elderly people sought medical assistance for shortness of breath, Hong Kong's radio RTHK reported.

Across the 100 mile-(160-kilometer)-wide Taiwan Strait, island residents covered their mouths to avoid breathing in the grit that can cause chest discomfort and respiratory problems even in healthy people. Sand covered cars in just 10 minutes and some flights were canceled due to poor visibility caused by the sandstorm. Grit from Chinese sandstorms has been found to travel as far as the western United States.

In the past decade, Beijing has sought to counter the effects of desertification by planting grasses and billions of trees to hold back the desert, mostly to no avail. Along with bringing pollution, the storms underscore a looming water crisis in the north that the government is seeking to head off with a massive project to pump water from the south.

Earlier, US Secretary of State Hillary Clinton told the meeting Israel should make "difficult choices" for peace. She said the continued expansion of Jewish settlements in Palestinian occupied territory undermined the US role in the peace process.

The Palestinian Authority is furious at Israel's insistence on building on occupied territory. It sees it as a serious stumbling block to the resumption of talks, which have been stalled for more than a year. Some 500,000 Jews live in more than 100 settlements built since Israel's 1967 occupation of the West Bank and East Jerusalem. They are considered illegal under international law, which Israel disputes.

The country's largest research agency, AC Nielson, estimates that figure will rise to about 25% this year - and the market to be worth an estimated $432 million, an all-time high. With the Indian middle class expected to increase 10-fold to 583 million people by 2025, it looks as if things will only get better. The implicit assumption by many is this: the whiter the skin, the more attractive you are.

Experts say that demand has boomed because of the tendency to discriminate against a person's skin colour, a practice which is still wide across rural India. "But if your complexion is fair, you avoid that pinch. Everyone in India wants to be fairer. At times it is repulsive, worse than chalking of geishas' faces in Japan but everyone wants to have a jar or tube of skin-whitening cream," says fashion designer Rohit Bal who has dressed Bollywood actresses and visited the sets of reality shows.

As a result, the products - priced between 50 cents and $150 a jar/tube - are in great demand countrywide. No study has ever been done to discover what "fairness in four weeks" achieves. Worse, there are several controversies attached to such products. "If you apply anything on the skin, there will obviously be side effects," says Rues VK Sharma, Head of the Dermatology Department at the All India Institute of Medical Sciences. "Very few know that many of these creams contain steroids. Whatever doctors say will always be a drop in the ocean, as advertisements flooding the market have a far larger impact on the minds of people."

At Perth airport, where part of the terminal roof collapsed, almost a month's average rainfall fell in just seven minutes, affecting flights. The freak storm hit Perth, one of the world's most isolated cities, late on Monday. Power cables collapsed, hospitals were flooded. Some schools remained closed on Tuesday.

Hailstones the size of golf balls smashed car windscreens. Driving became more dangerous when traffic lights went out. Weather forecasters said more stormy weather was expected, after one of the driest summers on record.

The volcano had been showing rumbles of activity for several days. Stream can be seen rising from the crater. Over the weekend, crowds of spectators gathered at viewpoints to marvel at the volcano, some wearing masks to keep out the dust. Spirit Lake, at the foot of the volcano, still contains debris from the more powerful eruption in 1980, which killed 57 people.

The volcano's reawakening has prompted much interest from reporters. And residents in the states of Washington and Oregon are also hoping to witness an eruption, though from a safe distance. The volcano is on highest eruption risk level, indicating there is a risk to life and property in the area.

"ASSASSINATION! America, we survived the Assassinations and Lincoln & Kennedy. We'll surely get over a bullet to Barrack Obama's head," wrote one Twitter user, who goes by the handle Solly Forell, and identifies himself as a conservative blogger and "'authentic' African American." Soon after the first post, Forell tweeted another message actively encouraging someone with a "clear shot" to kill the president.

"The next American with a Clear Shot should drop Obama like a bad habit. 4get Blacks or his claims to b[e] Black. Turn on Barack Obama," he wrote on the messaging Web site.

The Secret Service investigates any perceived threats to the president or calls for his assassination. "We are aware of the comments and are taking the appropriate investigative action. We respect the right of free speech, but in such instances we have a right and an obligation to ask questions and determine intent," the Secret Service told ABC News.

The office warned that the Firefox vulnerability, confirmed by Firefox makers, could allow hackers to run malicious programs on users' computers. A version of Firefox to be released at the end of the month will fix the bug. A "beta" or test version of that release, Firefox 3.6.2, is already available but has not yet been fully tested. The Federal Office for Information Security (BSI) has recommended that users stop using Firefox until the tested fix is released - in a move remarkably similar to the January announcement, in which France followed suit just days later.

The Firefox vulnerability was confirmed by maker Mozilla last week on its security blog, when it promised that the next official release would address the issue. It is only the current version, Firefox 3.6, that is affected, and given that prior releases have different vulnerabilities, reverting to an older version of the browser is ill-advised.

Only four months after the fanfare of Herman Van Rompuy's appointment as European Council president, his most jealous and powerful rival in Brussels has persuaded allies to allow him to muscle in too. Jose Manuel Barroso, president of the European Commission, has succeeded in his demands that he should also go to diplomatic summits, such as the G20, after insisting only he has the expertise to deal with specific policy matters.

At certain summits there will even be a third representative - the leader of the country holding the EU's rotating presidency. This seems to justify criticism that the Lisbon Treaty would add to the EU's murky waters and not be a move towards transparency. Sarah Gaskell, spokeswoman for the Open Europe think-tank, said last night: "This surely must be the final nail in the coffin of the Government's promise that the Lisbon Treaty would bring greater clarity to the European Union."

"Instead of Europe speaking with one voice we have two of the EU's many presidents fighting for the limelight and over who gets to speak on what issue. Other countries at the G20 will be completely puzzled by the EU's failure to decide who should speak for it. It seems to change from one day to the next."

Speaking on Sunday to the annual legal service in Wells Cathedral, Somerset, the bishop said the General Election would be held at the end of one of the most legislative parliaments in history, in which about 4,000 new laws had entered the statute book. "It can be argued that the cause of much of this legislation is as a result of the loss of community, the perceived breakdown of family life, and the decline of a sense of individual responsibility," he said.

"The effect of many of these new laws is to place responsibility for cleaning up the mess of society upon educationalists, doctors and health workers, social services, the police and other institutions and structure. Paradoxically, legislation on the rights of the individual has increased, leading to something of a victim society, as well as a blame culture. A culture of suspicion, accompanied by a climate of fear that to engage with strangers, even those evidently in need, is stultifying both innate social virtues and common good."

He added: "Most of us will have seen the adverts from some of the less scrupulous within the legal profession advising, 'Had any accident. Not your fault. You could make money.'" The bishop said that while the rights of the individual had increased, equivalent responsibility had decreased. "There is always someone or something to blame, whether it is background, social status or environment," he said. "Fault and accountability for one's own actions has been significantly diminished."

He added: "There is a perception, and perception is often all, that the principle of 'innocent until proven guilty' is effectively being reversed by much of the intrusive registration and monitoring currently enshrined in law."

It extends coverage to 32 million more Americans, and marks the biggest change to the US healthcare system in decades. "We proved that we are still a people capable of doing big things," Mr Obama said in remarks after the vote. "This legislation will not fix everything that ails our healthcare system, but it moves us decisively in the right direction," he said. Mr Obama is expected to sign the legislation into law shortly.

Under the legislation, health insurance will be extended to nearly all Americans, new taxes imposed on the wealthy, and restrictive insurance practices such as refusing to cover people with pre-existing medical conditions will be outlawed. The Republicans have vowed to continue resisting it. They say the measures are unaffordable and represent a government takeover of the health industry. "We have failed to listen to America," said Republican party leader John Boehner.

The $2.59 trillion of Treasury Department sales since the start of 2009 have created a glut as the budget deficit swelled to a post-World War II-record 10 percent of the economy and raised concerns whether the US deserves its AAA credit rating. The increased borrowing may also undermine the first-quarter rally in Treasuries as the economy improves.

"It's a slap upside the head of the government," said Mitchell Stapley, the chief fixed-income officer in Grand Rapids, Michigan, at Fifth Third Asset Management, which oversees $22 billion. "It could be the moment where hopefully you realize that risk is beginning to creep into your credit profile and the costs associated with that can be pretty scary."

"There's no natural law that says a Treasury has to yield less than a corporate," said Daniel Shackelford, who is part of a group that manages $18 billion in bonds at T Rowe Price Group Inc in Baltimore. "It wouldn't be the first time that I would scratch my head and say 'this doesn't make sense, the market's behaving irrationally.' And it can go on for much longer than you may think."

Monday is World Water Day, but I suspect relatively few will have noticed. Most people equate water consumption with what they use in their homes and places of work, but the challenge facing the globe goes much, much further than that. The 2030 Water Resources Group, a collaboration between the private and social sectors to discover solutions to combat water scarcity, estimates that global water requirements will grow by over 50% over the next 20 years. Such levels of usage will be 40% greater than what can currently be sustainably supplied.

Of course this global figure is an aggregation: at a more local level the situation is far worse. For example, by 2030 one third of the global population, mainly concentrated in developing countries, will have only half the amount of naturally renewed water available they need. What most consumers might not be aware of is that agriculture accounts for 70% of global water usage today, and how the need to feed the growing population of the world will put an even greater strain on already scarce water resources. And in recent years food and water supplies have also been significantly affected by the use of agricultural land and resources on the production of biofuels.

The 2030 Water Resources Group also predicts that industrial use of water will almost double by 2030. It currently accounts for 16% of total usage - more than half of it for energy production - and this will grow to a projected 22% by 2030 with China alone accounting for 40% of the additional demand. The challenge facing governments, businesses and - arguably - all of us, is how to close the gap in supply in a way that is both environmentally sustainable and economically viable. At the moment we are coping by 'borrowing' water supplies from non-replenishable aquifers or from water reserved for environmental needs, an approach which is clearly not a long-term solution.

The sooner governments, industry and consumers start to see the links between energy, food and water security, and how policies in one area affect another, the more likely it is that water scarcity will get the profile it deserves and that we start acting decisively to assure the sustainability of humankind's most precious resource, water.

John Lipsky, the International Monetary Fund's first deputy managing director, said the scale of the adjustment required was so vast that it would have to come through less-generous health and pension benefits, spending cuts and increased tax revenues. "Addressing this fiscal challenge is a key near-term priority, as concerns about fiscal sustainability could undermine confidence in the economic recovery," Lipsky told the China Development Forum.

"Already in several countries with particularly high debt and deficits, sovereign risk premia have risen sharply, imposing strains for the countries affected and raising risks of possible broader spillovers," he said in remarks prepared for delivery to the conference. For most advanced economies, maintaining fiscal stimulus in 2010 remains appropriate, but consolidation should begin next year if the global economic recovery remains on track.

He painted a daunting picture of the tightening needed to restore public finances to health. Gross general government debt in the advanced economies will rise from an average of 75 percent of GDP at end-2007 to 110 percent of GDP at end-2014, even assuming that temporary, crisis-related stimulus steps are withdrawn in coming years. Reducing the ratio to the pre-crisis average of 60 percent by 2030 would require raising the structural primary balance - before interest payments - from a deficit of about 4 percent of GDP in 2010 to a surplus of about 4 percent of GDP in 2020 and keeping it at that level for the following decade.