12 feared dead after US military helicopter crash in Hawaii

Two United States Marine helicopters flying off the coast of Hawaii collided mid-air around midnight Friday morning.

The Pentagon confirmed the news with NBC saying there were 12 Marines aboard. So far there is no sign of survivors.

Coast Guard personnel in the area told CBS news they arrived on scene just after midnight local time to find a debris field, an empty life raft and fire on the water about 2.5 miles (around 4 kilometres) off Oahu’s North Shore.

WATCH: Officials say the incident was part of a routine training mission with 6 crew aboard each aircraft.

4:10 12 Marines are identified as missing after two helicopters crash

Media reports say the US Navy and Coast Guard have both deployed helicopters and boats to assist in the search.  Marine Capt. Timothy Irish said the two CH-53s were from the 1st Marine Aircraft Wing from Marine Corps Base Hawaii.

WATCH: Military officials said a civilian witnessed the helicopter crash from shore

0:26 Civilian witnessed helicopter crash from shore

Search efforts are being limited by large waves in the area, with the largest swell of the season expected to roll in on Friday according to Hawaii News Now.

With a file from The Associated Press.