UPDATE March 26, 2:36 p.m.:
The Guardian reports the laptop ban in the U.S. and U.K. was partly due to a plot to sneak a bomb on a plane in a fake iPad.
The U.K. version of the ban took effect Saturday. An anonymous source told The Guardian the fake iPad was a dead ringer for a real one. The reason the devices were banned from the cabin, rather than outright, is that a bomb in the cabin can be positioned to do much more damage than a bomb int he cargo hold, where a would-be terrorist can't control where the explosives end up.
UPDATE March 22, 7:42 a.m.:
Intelligence reports show that al-Qaida in the Arabian Peninsula (AQAP) was perfecting methods to hide bombs in batteries and battery compartments of electronic devices, CNN reports. This intelligence led the U.S. and the United Kingdom to ban electronic devices bigger than a phone on certain international flights.
The International Civil Aviation Organization warned regulators last year shipping lithium-ion batteries in bulk in cargo holds could be a fire hazard.
UPDATE March 21, 12:39 p.m.:
The United Kingdom is considering adopting a similar ban on personal electronics on inbound flights from the Middle East and Africa, CNN reports.
Prime Minister Theresa May is aware of the same intelligence reports that sparked the U.S. ruling and may announce an official decision later Tuesday.
UPDATE March 21, 7:12 a.m.:
The Department of Homeland Security's new restrictions on passengers from certain foreign nations have been revealed, and they target eight Muslim-majority countries.
The Washington Post reports passengers from ten airports in Egypt, Jordan, Kuwait, Morocco, Qatar, Turkey, Saudi Arabia and the United Arab Emirates are affected. Passengers arriving from those airports will not be required to put personal electronic devices bigger than a phone in their checked baggage.
The rules were prompted by intelligence reports that terrorists were planning to "smuggle explosives in portable electronic devices." Officials cited the example of a bomb, possibly hidden in a laptop, that exploded on a Somali plane headed from Mogadishu to Djibouti. However, an anonymous source told the Post officials have feared similar attacks for years.
Airlines will have 96 hours to comply with the new rules or risk losing their authorization to operate in the U.S. Phones and medical devices are excluded from the ban.
ORIGINAL STORY: The Department of Homeland Security is expected to announce Tuesday plans to ban passengers on certain U.S.-bound foreign flights from carrying large electronic devices into the cabin of the aircraft, Reuters reports.
The restrictions come in response to an unspecified terrorist threat and the security concern involves passengers boarding non-stop flights to the U.S.
An aviation official told CNN U.S. airlines will not be affected because none of them fly directly from the countries in question.
A State Department official also told CNN "embassy officials have been notifying relevant countries and airlines."
The ban will likely impact 10 airports in eight countries in the Middle East and Africa. At least two airlines have already tweeted about the new guidelines, however, Royal Jordanian deleted its tweet shortly after it was posted.
Both Middle Eastern-based airlines tweeted that laptops, Kindles, and iPads are among the devices that passengers would have to check.
The deleted tweet from Royal Jordanian said this was a directive from "concerned U.S. departments," but didn't offer further details.
USA Today reports that this may be an update to a July 2014 requirements that said passengers must turn on electronics before boarding foreign, U.S.-bound flights.