The US is banning electronic devices from cabin baggage on flights from eight mainly Middle Eastern and North African countries.
A US government source told the BBC that the measure would affect nine airlines operating out of 10 airports.
US media reported the order was sparked by intelligence gathered overseas.
It will reportedly include all large electronic devices such as laptops, tablets cameras, DVD players and electronic games, but not phones.
Medical devices will also be exempt from the ban.
The Department of Homeland Security (DHS) declined to comment on the issue but is expected to make an announcement on Tuesday.
The Transportation Security Administration (TSA), which is part of Homeland Security, also refused to comment.
A formal list of the airlines affected has yet to be released, but an official speaking to the Associated Press (AP) said it would apply to the following 10 airports in eight countries:
- Queen Alia International, Amman, Jordan
- Cairo International Airport, Egypt
- Ataturk Airport, Istanbul, Turkey
- King Abdulaziz International, Jeddah, Saudi Arabia
- King Khalid International, Riyadh, Saudi Arabia
- Kuwait International Airport
- Mohammed V International, Casablanca, Morocco
- Hamad International, Doha, Qatar
- Dubai International, United Arab Emirates
- Abu Dhabi International, United Arab Emirates
Officials said the ban had no end date. AP reported that airlines would not be officially informed of the ban until 03:00 ET (07:00 GMT) on Tuesday.
But Royal Jordanian Airlines tweeted on Monday that it would ban passengers from carrying on most electronics to and from its North American flights.
The tweet was later deleted.
Source: BBC