The United States warned Tuesday that extremists plan to target planes with bombs hidden in electronic devices, and banned carrying them on certain flights.
The flights affected are those originating from 10 airports in Turkey, the Middle East and North Africa.
Senior US officials told reporters that nine airlines from eight countries had been given 96 hours, beginning 07:00 GMT, to ban any device bigger than a cellphone or smartphone from the cabin.
Laptops, tablets and portable game consoles are affected by the ban -- which applies to direct flights to the United States -- but they may still be stowed in the hold in checked baggage.
Passengers on approximately 50 flights per day from some of the busiest hubs in the Middle East, Turkey and North Africa will be obliged to follow the new emergency ruling.
"The restrictions are in place due to evaluated intelligence and we think it's the right thing to do and the right places to do it to secure the safety of the traveling public," one US official said.
The airports touched by the ban are Queen Alia International in Amman, Jordan; Cairo International in Egypt; Ataturk in Istanbul, Turkey; King Abdulaziz International in Jeddah, Saudi Arabia; King Khalid International in Riyadh, Saudi Arabia; Kuwait International; Mohammed V International in Casablanca, Morocco; Hamad International in Doha, Qatar; and the Dubai and Abu Dhabi airports in the United Arab Emirates.
No US carriers make direct flights from these airports, so they are unaffected by the ban, which will hit Royal Jordanian, EgyptAir, Turkish Airlines, Saudi Airlines, Kuwait Airways, Royal Air Maroc, Qatar Airways, Emirates and Etihad Airways.
The airlines and their host governments have already been informed of the order by US officials, and some of them have begun informing passengers about the restriction.
Airlines will be responsible for policing the cabin ban, and if they fail to do so could lose their rights to operate US routes.
No end date has been put on the order, and officials would not say whether the restriction might spread to other airports.
