WASHINGTON – Questions are being raised about whether passengers on some U.S. flights might be facing new restrictions barring laptops and other electronics from being brought onboard in carry-on luggage.

The uncertainty comes after Royal Jordanian Airlines somewhat cryptically warned passengers Monday that electronic devices such as laptops, cameras and DVD players would be “strictly prohibited” in the cabin on its flights to the United States and must be checked.

The prohibition is scheduled to begin Tuesday and involves Royal Jordanian flights to New York, Chicago and Detroit, according to an airline tweet. Royal Jordanian’s flights to Montreal, which currently continues on to Detroit, would also be affected. The restriction doesn’t apply to cell phones or medical devices "needed during flight."

In its tweet, Royal Jordanian referenced “instructions from the concerned U.S. departments" but did not offer further details.

Also not immediately clear were how many airlines or airports a possible electronics restriction might affect. Of a dozen foreign airlines contacted Monday afternoon, Royal Jordanian was the only one to publicly detail such a prohibition on electronics.

In the absence of specific details, the restriction appears to be an enhancement of requirements in July 2014 that required travelers to turn on electronics before boarding overseas headed to the U.S.

But while that 2014 guidance was formally announced, security officials were tight-lipped Monday about any additional changes that might be afoot following Royal Jordanian’s move.

The Transportation Security Administration, which ensures that security meets U.S. standards at airports that send flights to the U.S., and the Department of Homeland Security each said: “We have no comment on potential security precautions, but will provide any update as appropriate.”

The 2014 tightening of security -- since relaxed -- came after the department warned about terrorists developing new strategies for hiding explosives on flights. If electronic devices couldn’t be turned on, they weren’t allowed in the cabin.