A really unusual step has been taken by the U.S air safety regulators by singling out the new Samsung Galaxy Note 7 smartphone and labeling it as a potential airborne fire hazard. In a brief but strongly worded statement released late Thursday, the Federal Aviation Administration (FAA) said that “in light of recent incidents and concerns” involving the smartphones, the agency “strongly advises passengers not to turn on or charge these devices” on planes and “not to stow them in any checked baggage.”

Identifying a specific brand or model as a potential hazard is a highly unusual move for the FAA, though agency officials previously issued warnings about the overall dangers of checking any kind of cellphones, other battery-powered electronic devices or spare batteries in the holds of airliners. The lithium-ion batteries that typically power such mobile devices can short-circuit or otherwise heat up and cause fires.

The statement comes less than a week after Samsung, the world’s largest smartphone maker by shipments, announced a global recall and replacement program for millions of Galaxy Note 7 devices because of batteries exploding or catching fire.

The FAA’s statement didn’t cite any specific incidents. Samsung said Friday it was discussing the FAA move internally and declined to comment further.

South Korea’s air-safety regulator said it has no plans to ban Galaxy Note 7 devices on airlines or take measures to prevent passengers from using or charging the device during flights.

Shares in the company fell 2.7% following the news.

Samsung has said it shipped 2.5 million units of the Galaxy Note 7 since its launch on Aug. 19. In the U.S., the phone has a suggested retail price of more than $800.

Samsung has used its popular Galaxy phones to boost its mobile business, which has been struggling for more than two years amid strong competition from  Apple Inc. and Chinese rivals.

In recent years, the FAA, numerous foreign air-safety regulators and airlines around the globe have started cracking down on spare batteries or battery-powered mobile devices placed in any bags that end up being loaded into aircraft bellies. Most airlines have a specific ban on putting such devices or batteries inside checked baggage.