The US Department of Transportation (DOT) has issued an emergency order banning Samsung Galaxy Note7 smartphones from being transported by air in the US—either by passengers or as air cargo—because of fire concerns. The ban went into effect Oct. 15 at 12 p.m. eastern time in the US.

“If passengers attempt to travel by air with their Samsung Galaxy Note7 devices, the phones may be confiscated and passengers may face fines,” DOT said in a statement issued Oct. 14 in conjunction with FAA and the US Pipeline and Hazardous Materials Safety Administration (PHMSA). “Passengers who attempt to evade the ban by packing their phone in checked luggage are increasing the risk of a catastrophic incident.Anyone violating the ban may be subject to criminal prosecution in addition to fines.”

The statement instructs US airline staff that ifthey observe a passenger “in possession of a Samsung Note7 device prior to boarding an aircraft, the air carrier must deny boarding to the passenger unless and until the passenger divests themselves and their carry-on and checked baggage of the Samsung Galaxy Note7 device. Passengers absolutely should not pack the phones in their checked luggage.”

If a flight crew member spots a Samsung Galaxy Note7 device aboard an aircraft already inflight, “the crew member must instruct the passenger to power off the device, not use or charge the device while aboard the aircraft, protect the device from accidental activation, including disabling any features that may turn on the device, such as alarm clocks, and keep the device on their person and not in the overhead compartment, seat back pocket, nor in any carry-on baggage, for the duration of the flight,” DOT said.

FAA had previously warned airline passengers not to use Samsung Galaxy Note7 devices on board aircraft, but there were no legal consequences that went with that warning. On Oct. 5, a Southwest Airlines Boeing 737-700 preparing for takeoff from Louisville, Kentucky was evacuated because of a smoking smartphone FAA confirmed was a Samsung device.

“We recognize that banning these phones from airlines will inconvenience some passengers, but the safety of all those aboard an aircraft must take priority,” US transportation secretary Anthony Foxx said in a statement. “We are taking this additional step because even one fire incident inflight poses a high risk of severe personal injury and puts many lives at risk.”

Samsung issued a recall on the original Note7 in September, followed by another recall of replacement Note7 devices on Oct. 13. Samsung suspended Note7 manufacturing on Oct. 11.

Aaron Karp