The White House just launched a new set of travel restrictions targeting Muslim countries

On Monday evening, the Trump administration announced a new set of rules which banned many types of electronics from the cabins of foreign-owned and operated flights originating from 10 airports in eight predominantly Muslim nations.

The new rule, which forbids passengers from carrying electronics larger than a cell phone—including many airplane mainstays such as laptops, e-readers, and tablets—went into effect at 3 AM EST Tuesday morning. Moving forward, these items may now only be checked into baggage. A now-deleted tweet from Royal Jordanian airlines also claimed that medical devices were exempt from the policy.

An unnamed senior administration official speaking with the Washington Post cited unspecified threats which prompted the new policy.

“Based on this information,” the official explained, “Secretary of Homeland Security John Kelly and Transportation Security Administration acting administrator Huban Gowadia have determined it is necessary to enhance security procedures for passengers at certain last-point-of-departure airports to the United States.”

However, a separate official with the Transportation Security Administration suggested to the New York Times that the new policy was perhaps being rushed, confirming to the paper that not everyone in that agency had been briefed on the new rules as of Monday evening, when news of the directive broke.

The new policy comes days after the White House suffered a series of stinging judicial rebukes on its second attempt at a Muslim travel ban—portions of which were temporarily halted by judges in Hawaii and Maryland. In response, the administration has vowed to appeal the rulings.

This new policy covers airports in Jordan, Egypt, Kuwait, Turkey, Morocco, Saudi Arabia, United Arab Emirates, and Qatar. According to the Washington Post, airlines have 96 hours to implement the changes.