PENSACOLA, Fla. -- Seven Marines and four soldiers are missing early Wednesday after an Army helicopter crashed during a night training exercise at Eglin Air Force Base in the Florida Panhandle.

Base officials say the Marines are part of a Camp Lejeune-based special operations group and the soldiers are from a Hammond, Louisiana-based National Guard unit.

Eglin spokesman Andy Bourland says the helicopter was reported missing around 8:30 p.m. Tuesday and search and rescue crews found debris from the crash around 2 a.m. Wednesday.

The helicopter went down during a routine training mission on a remote swath of beach between Pensacola and Destin. The beach is owned by the military and is used for test missions.