The attack, for which Houthi rebels battling Saudi Arabia in Yemen took credit, underscored the fears raised by US security officials and experts in terrorism about the rapid evolution of technologies allowing expanded unmanned flight. “The bottom line is that we are likely to see many more of these sorts of attacks, and in particular, coordinated attacks on multiple targets are likely, possibly in tandem with a cyber attack component,” Milena Rodban, an independent risk consultant based in Washington, said in an email.

The implication of Saturday’s attacks are enormous, Price said. They not only highlight the growing technical capability of rebel groups, but could also serve as inspiration for home-grown terrorists in the US who may be motivated by the Islamic State or al-Qaeda, he said. “Flying a drone, that puts a new spin on things,” he said. “It enables attacks that previously weren’t able to be conducted with that level of stealth and detachment from the attacker.”