American officials have ordered some overseas airports to heighten security checks on US-bound flights, measures that include closer screening of electronic devices, Digital Spy reported.

The new regulations will require passengers to switch on their smartphones, tablets and laptops prior to boarding to prove that they are real.

This means that devices with no battery life must be left behind, unless the traveller is willing to abandon their flight.

"During the security examination, officers may also ask that owners power up some devices, including cell phones," said US government body the Transportation Security Administration.

"Powerless devices will not be permitted onboard the aircraft. The traveller may also undergo additional screening."

London's Heathrow airport is among the overseas sites implementing the new measures, according to BBC News.

Transport officials in the US announced the policy last week, but did not clarify why increased security is required.