SAN DIEGO (AP) - The U.S. Marine Corps says a collision between two helicopters that killed seven Marines happened on the California side of the Chocolate Mountains close to the Arizona border.

Lt. Maureen Dooley with the Miramar Air Base in California says Wednesday night's crash during training involved an AH-1W "Cobra" that carries two crew members and a UH-1 "Huey" helicopter.

The aircraft from Camp Pendleton, Calif., collided in a remote portion of the Yuma Training Range Complex.

The U.S. military and its allies train in the hot, desert area ringed by mountains because the conditions are similar to Iraq and Afghanistan.

It was the most recent of several accidents in the past year involving Marine Corps training in Southern California.