San Diego, California - Five US service members missing after their helicopter crashed this week in southern California have been confirmed dead, the US Marine Corps said Thursday.

The CH-53E Super Stallion helicopter crashed Tuesday while flying from Creech Air Force Base in Nevada to Marine Corps Air Station Miramar, outside San Diego, the military said.

"It is with a heavy heart and profound sadness that I share the loss of five outstanding Marines from 3d Marine Aircraft Wing and the 'Flying Tigers' while conducting a training flight," Major General Michael Borgschulte, commander of the Third Marine Aircraft Wing, said in a statement.

The Marine Corps said efforts to recover the remains of the crash victims have begun and an investigation is underway.

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President Joe Biden said he was "heartbroken" at the loss of the service members.

"We extend our deepest condolences to their families, their squadron, and the US Marine Corps as we grieve the loss of five of our nation's finest warriors," he said in a statement.

There have been a series of accidents involving US military aircraft over the past year, including the crash of a V-22 Osprey tilt-rotor aircraft off the coast of Japan in late November that left eight airmen dead.

Five American service members were killed when a helicopter crashed into the Mediterranean during a training exercise earlier the same month, while another Osprey crash in Australia left three Marines dead in August.

Three more military personnel were killed and another injured when two helicopters returning from a training mission in a remote area of Alaska collided in April.