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Due to an unspecified terrorism threat, passengers on some flights bound for the United States will not be allowed to carry electronic devices larger than a cellphone inside the airplane's cabin, U.S. officials told Reuters Monday.

The rule has been under consideration since the government became aware of the threat several weeks ago, the official said, and could be announced by the Department of Homeland Security Monday night. The ban covers a dozen foreign airlines flying from a dozen countries, including Saudi Arabia and Jordan. While passengers won't be able to carry the larger devices into the cabin, they will be able to have such items in their checked bags.