Boarding plane? Power up your phone...
AIR travellers with smartphones or other electronic devices must be able to switch them on to take them aboard under new security measures, the United States said on Sunday.
The checks were focused on electronic items such as laptops and smartphones, amid fears that extremist groups such as Al-Qaeda could use them as their latest tactic in a long campaign of attacks involving jets.
"During the security examination, officers may...ask that owners power up some devices, including cellphones," the US Transportation Security Administration (TSA) said in a statement, noting that all electronic devices are screened by security officers.
"Powerless devices will not be permitted on board the aircraft. The traveller may also undergo additional screening."
The agency noted that it could "adjust" security measures further to provide maximum security to travellers.
US-bound travellers from Europe and the Middle East have faced tighter airport security in recent days, over fears that militants linked to Al-Qaeda are developing new explosives that could be slipped into planes undetected.
The French and British authorities have urged passengers to set aside extra time to accommodate the additional measures, which were not specified but were believed to focus on footwear and electronic items.
The Department of Homeland Security (DHS), of which the TSA is a part, is also asking that airlines and the airport authorities in Europe and elsewhere examine the shoes of passengers headed for the US, and increase random screenings of travellers, ABC News reported.
It cited a source as saying that the unspecified threat was "different and more disturbing than past aviation plots".
"We felt that it was important to crank it up some at the last point-of-departure airports," DHS Secretary Jeh Johnson told NBC television's Meet The Press.
"And we'll continually evaluate the situation.
"We know that there remains a terrorist threat to the United States. And aviation security is a large part of that," he added.