Officials in the US say some passengers at overseas airports will be told to turn on electronic devices as part of new security measures.
The Transportation Security Administration (TSA) said it will require s ome foreign airports to order passengers to turn on devices such as mobile phones. Any that do not power up will not be allowed on flights to the US, and those travellers may have to undergo additional screening.
Homeland Security Secretary Jeh Johnson recently ordered the TSA to put extra security measures in place at some international airports with direct flights to the United States.
American intelligence officials have been concerned about new al-Qaida efforts to produce a bomb that would go undetected through airport security.
The TSA will not disclose which airports will be conducting the additional screening.