A US military helicopter with five soldiers on board has crashed in Southern California. This was announced by the US Marine Corps on Wednesday (local time) on Twitter.

The machine belonged to the 3rd Marine Aircraft Wing, the San Diego-based unit confirmed in a statement. However, the US military initially did not comment on possible victims or the cause of the accident. “Five Marines were on board the aircraft and we are awaiting confirmation of the status of all crew members,” it said.

The Los Angeles Times reports at least four fatalities, citing unnamed sources.

The crash reportedly happened near the town of Glamis, about 35 kilometers from the border with Mexico and a good 200 kilometers east of San Diego.

According to the military, the helicopter was an MV-22B Osprey machine. The model has rotating wings that can be raised, giving it the maneuverability of a helicopter.