Horn of Africa ? Two U.S. Marine Corps helicopters crashed Friday off the coast of northern Djibouti, and rescuers were searching for 10 missing crew members Friday night, according to U.S. military officials in the Horn of Africa.

Investigators were looking into the cause of the crash, which officials said happened during a training mission over the Gulf of Aden near Ras Siyyan.

A spokeswoman for the military’s task force in the Horn of Africa said it was unclear whether the helicopters collided, and she did not have further details of the crash or weather conditions at the time.

Djiboutian military near where the helicopters hit were able to respond immediately and rescued two crew members from the water, according to a U.S. Central Command news release. Those two crew members suffered injuries and were in stable condition at Camp Lemonier, a U.S. base in Djibouti.