In Japan and South Korea, some manufacturers for the first time have begun buying genetically engineered corn for use in soft drinks, snacks and other foods. Until now, to avoid consumer backlash, the companies have paid extra to buy conventionally grown corn. But with prices having tripled in two years, it has become too expensive to be so finicky. "We cannot afford it," said a corn buyer at Kato Kagaku, a Japanese maker of corn starch and corn syrup.

In the United States, wheat growers and marketers, once hesitant about adopting biotechnology because they feared losing export sales, are now warming to it as a way to bolster supplies. Genetically modified crops contain genes from other organisms to make the plants resistant to insects, herbicides or disease. Opponents continue to worry that such crops have not been studied enough and that they might pose risks to health and the environment.

"I think it's pretty clear that price and supply concerns have people thinking a little bit differently today," said Steve Mercer, a spokesman for U.S. Wheat Associates, a federally supported cooperative that promotes American wheat abroad. Biotechnology still certainly faces obstacles. Polls in Europe do not yet show a decisive shift in consumer sentiment, and the industry has had some recent setbacks. Since the beginning of the year France has banned the planting of genetically modified corn while Germany has enacted a law allowing for foods to be labeled as "GM free."

Major retailers in New York, in areas of New England, and on the West Coast are limiting purchases of flour, rice, and cooking oil as demand outstrips supply. There are also anecdotal reports that some consumers are hoarding grain stocks. At a Costco Warehouse in Mountain View, California, yesterday, shoppers grew frustrated and occasionally uttered expletives as they searched in vain for the large sacks of rice they usually buy.

"Where's the rice?" an engineer from Palo Alto, said. "You should be able to buy something like rice. This is ridiculous." The bustling store in the heart of Silicon Valley usually sells four or five varieties of rice to a clientele largely of Asian immigrants, but only about half a pallet of Indian-grown Basmati rice was left in stock. A 20-pound bag was selling for $15.99.

An employee at the Costco store in Queens said there were no restrictions on rice buying, but limits were being imposed on purchases of oil and flour. Internet postings attributed some of the shortage at the retail level to bakery owners who flocked to warehouse stores when the price of flour from commercial suppliers doubled.

The curbs and shortages are being tracked with concern by survivalists who view the phenomenon as a harbinger of more serious trouble to come.

"It's sporadic. It's not every store, but it's becoming more commonplace," the editor of SurvivalBlog.com, James Rawles, said. "The number of reports I've been getting from readers who have seen signs posted with limits has increased almost exponentially, I'd say in the last three to five weeks."

After meeting Hamas leaders last week in Syria, he said it was a problem that the US and Israel would not meet them. US Secretary of State Condoleezza Rice has challenged Hamas to prove its goodwill by renouncing violence. Israeli Prime Minister Ehud Olmert has refused to see Mr Carter, who was ending his regional visit in Jerusalem.

Meanwhile, the Israeli army has launched a formal investigation into the death of a Reuters cameraman killed in the Gaza Strip last week. Two Palestinians died in Israeli air strikes in the territory on Monday: one person in the southern city of Rafah and a Hamas militant at Beit Hanoun, a border town from where rockets are often fired at Israel.

Speaking in Manama on a tour of the Middle East, Ms Rice said Hamas should show their willingness to make peace by releasing Corp Shalit and halting rocket attacks on Israel. She also called on the group to recognise the legitimacy of the Palestinian Authority, whom they ousted from Gaza last summer.

The Tibet Daily newspaper said the campaign was to "unify the thinking? of officials and the masses". The initiative follows violent clashes last month between police and monks in Tibet, and pro-Tibetan demonstrations around the world. Beijing has accused the Dalai Lama of inciting unrest - claims he has denied.

The Tibetan spiritual leader, who lives in exile in India, insists he has no political role and played no part in the protests by Tibetan Buddhist monks that erupted into rioting in the main city Lhasa. He condemned the Chinese crackdown that followed, and accused Beijing of committing "cultural genocide" in Tibet. Tibetan sympathisers and human rights activists have since used the worldwide tour of the Olympic torch to protest against Beijing's hosting of the Olympic Games this August.

China's Communist Party has long used what it calls "patriotic education campaigns" to impose discipline and reinforce its authority, says the BBC's Daniel Griffiths in Beijing. The Tibet Daily says the latest drive will include television programmes and a series of sessions in which the Dalai Lama will be denounced by Communist Party members, other officials and local people. Campaigns requiring monks in Tibetan monasteries to denounce the Dalai Lama and declare their loyalty to Beijing have also been stepped up.

China has poured troops into Tibet and tightened its borders ahead of the passage of the Olympic flame through the territory, on its way to Mount Everest in early May. It accuses the Dalai Lama of wanting to divide Tibet from China and sabotage the Olympics.

The first minister urged bosses and unions to reopen negotiations and also outlined the government's contingency plans for a total shut-down. If no deal can be struck between operators Ineos and the Unite union, up to 1,200 workers will walk out. Ineos says the refinery will shut down totally on Friday prior to the strike.

Production is expected to be hit from Monday as the first of the crude oil units is closed in a phased shutdown of the refinery, one of only nine in the UK. If the strike does go ahead, he said the government is taking measures to secure fuel supplies and has asked emergency services, local authorities and key agencies to get together and discuss needs at a local level over the next two days. Drivers have been urged not to panic buy at the forecourts.

However, national officer Phil McNulty accused the company of "scaremongering" about possible petrol shortages in Scotland and the north of England in the next few days. He said: "The company appears to be inundating the press with stories about imminent petrol shortages, but the fact is that the refinery is still in full production and there is no industrial action going on. Indeed, there is no need for any shortages if the company simply withdraws its outlandish attempt to grab money back from the pension fund."

Banks will be able to swap potentially risky mortgage debts for £50bn of secure government bonds to enable them to operate during the credit squeeze. The Bank's governor, Mervyn King, said the scheme aimed to improve liquidity in the banking system. It should also increase confidence in financial markets, he added. Under the scheme, banks will be allowed to swap their "high quality" mortgage debts for government securities.

The swap will be for a period of one year and may be renewed for a total of three years. It will only apply to mortgage debts on banks' books at the end of 2007 and the swaps cannot be used to finance new lending. British banks have become increasingly unwilling to lend to one another as a result of the credit crisis, which was triggered by massive losses for banks involved in the US sub-prime mortgage market. Many investors, concerned at what happened to sub-prime mortgages in the US, no longer want UK mortgage-based assets. The disappearance of this market has deprived banks of tens of billions of pounds of finance for mortgage lending.

However, the BBC's business editor Robert Peston said the move could be seen as a major U-turn by the Bank. Until now, the Bank of England has been more conservative in its financial support for banks than the Federal Reserve in the US and the European Central Bank. In the US, the Federal Reserve took similar action with a $200bn programme to boost liquidity in financial markets last month.

More than 234,000 properties were in some stage of foreclosure, or one in every 538 U.S. households, Irvine, California-based RealtyTrac Inc., a seller of default data, said today in a statement. Nevada, California and Florida had the highest foreclosure rates. Filings rose 5 percent from February. About $460 billion of adjustable-rate loans are scheduled to reset this year, according to New York-based analysts at Citigroup Inc. Auction notices rose 32 percent from a year ago, a sign that more defaulting homeowners are "simply walking away and deeding their properties back to the foreclosing lender" rather than letting the home be auctioned, RealtyTrac Chief Executive Officer James Saccacio said in the statement.

"We're not near the bottom of this at all," said Kenneth Rosen, chairman of Rosen Real Estate Securities LLC, a hedge fund in Berkeley, California and chairman of the Fisher Center for Real Estate at the University of California at Berkeley. "The foreclosure process will accelerate throughout the year." Rising foreclosures will add more inventory to an already glutted market, keep home prices down through at least next year and thwart efforts by Congress and President George W. Bush to help homeowners avoid default, Rosen said in an interview.

Britain's biggest supermarket said pre-tax profits were up 11.8% on the year before. UK sales increased by 3.5% on a like-for-like basis, excluding petrol, in the year to February 23 as Tesco said it coped with a particularly tough second half. The group has been under increasing pressure from competitors Morrisons and Asda as the supermarkets gain market share.

Tesco, which has around 30% of the UK grocery market, said the past year had been "unusual", with belt tightening among hard-pressed consumers also seeing subdued sales of some non-food products in the final six months.

"The torch escorts are volunteers, they are not law-enforcement personnel. Their duty is to maintain the safety, purity and dignity of the Olympic Games," China's foreign ministry spokeswoman Jiang Yu told reporters. "We hope the relevant countries can fully understand this point and co-operate with us."

It was still unclear on Tuesday whether China's "security runners" would be issued visas to enter Japan. One government official said Japan was surprised Chinese security forces were allowed to enter other countries that had hosted the relay.

"The Chinese torch attendants have a practical responsibility in relation to servicing the flame, but have no responsibility in terms of security," Mr Rudd, Australia's prime minister, said. "This has been made clear to the Chinese authorities. Under no circumstances, no matter what occurs, will they be called upon to perform a security function."

Pakistan, a loyal ally of China that is due to receive the torch on Wednesday, has also made a last-minute change to the route, confining all ceremonies to a tightly guarded stadium in the capital and cancelling a procession along Constitution ­Avenue, Islamabad's main boulevard.

An interior ministry official in Islamabad said the government was concerned about the possibility of suicide attacks. Groups thought to be linked to Muslim Uighur militants opposed to China's rule in Xinjiang, the only Chinese province or "autonomous" region with a Muslim majority, have in the past targeted Chinese nationals in Pakistan.

"We are not prepared to take any chances," the official said. Pro-Tibet protests have never taken place in Pakistan and Pervez Musharraf, the country's president, during a recent visit to China strongly condemned disruptions of the relay, saying politics should be kept out of sport.

From Islamabad, the torch will travel to New Delhi, where a nervous government has trimmed the route from fear that Tibetan protesters might try to disrupt the procession. The route is still to be announced but the Indian media has reported that the torch will travel less than a third of the original 9km route.

The aid charity, Oxfam, has warned that 60 million people in Asia, Africa and South America are threatened with possible eviction to make way for "green" fuel plantations, whether palm oil, soya or sugar cane. The Royal Society for the Protection of Birds accuses the Government today of overlooking the likely impact on endangered species of biofuels production, which is costing the taxpayer £500 million in subsidies.

"The reality is that people are dying already," said Jacques Diouf, of the UN's Food and Agriculture Organization (FAO). "Naturally people won't be sitting dying of starvation, they will react," he said. The UN says it takes 232kg of corn to fill a 50-litre car tank with ethanol. That is enough to feed a child for a year. Last week, the UN predicted "massacres" unless the biofuel policy is halted. We are all part of this drama whether we fill up with petrol or ethanol. The substitution effect across global markets makes the two morally identical.

Mr Diouf says world grain stocks have fallen to a quarter-century low of 5m tonnes, rations for eight to 12 weeks. America - the world's food superpower - will divert 18pc of its grain output for ethanol this year, chiefly to break dependency on oil imports. It has a 45pc biofuel target for corn by 2015. Argentina, Canada, and Eastern Europe are joining the race.

"The world food situation is very serious: we have seen riots in Egypt, Cameroon, Haiti and Burkina Faso," said Mr Diouf. "There is a risk that this unrest will spread in countries where 50pc to 60pc of income goes to food," he said. Roughly 100m people are tipping over the survival line. The import ratio for grains is: Eritrea (88pc), Sierra Leone (85pc), Niger (81pc), Liberia (75pc), Botswana (72pc), Haiti (67pc), and Bangladesh (65pc).

Josette Sheeran, who heads the Rome-based U.N. agency, said commodity and fuel costs had risen "even more dramatically" since it made its appeal. The price WFP pays for rice, a staple in many poor countries, jumped from around $460 a metric ton in the beginning of March to $780 a metric ton now, Sheeran told a U.S. government conference on food aid.

Donor countries and aid groups are struggling to stretch budgets to match soaring food prices, which have taken off in the past few years as new investment money pours into commodity markets and biofuel production consumes more of the world farm output. Global food prices increased close to 40 percent in 2007, and prices are expected to remain high for at least two to three years.

"Constant monitoring of the situation will be maintained," said a statement from Colombia's Interior Ministry. The volcano, in the province of Huila, is not located near any major coffee plantations integral to the economy of this part of the Andean country.

Nevado del Huila erupted at the start of 2007 after laying dormant for hundreds of years. A 1985 eruption of the Nevado del Ruiz volcano in Caldas province triggered mudslides killing 25,000 people in Colombia's worst natural disaster.

In recent years, the US Catholic Church has been hit by a wave of accusations that clergy abused children and has paid some $2bn (£1bn ) in settlements. During his trip, the Pope will address the UN, celebrate two masses, pray at Ground Zero and visit a synagogue. "We will absolutely exclude paedophiles from the sacred ministry," the Pope told reporters on board the flight to Washington.

The sexual abuse by clergy had been a great suffering for the US Catholic Church, the Church in general and for him personally, the Pope said. "I am deeply ashamed and will do whatever is possible so that this does not happen in the future," he said. "It is more important to have good priests than many priests. We will do everything possible to heal this wound."

The Pope has been asked to meet some victims of clerical abuse and their families during his visit but has so far declined to do so, the BBC's Rome correspondent David Willey says. The Pope will celebrate his birthday during the trip, turning 81 on Wednesday.

He says: "The fact that we are going to have a real president, a permanent president of the continent, will be a particular achievement I think. A prominent representative for foreign affairs, I think, will change the face of Europe, especially in the eyes of the rest of the world." Returning to the subject of EU President he added, "Today we have Commissioners, we have members of the European Parliament, but we have no real leader in fact. An EU president will be a real leader and will change the face of Europe."