Two Malaysian navy helicopters collided in mid-air during a rehearsal on Tuesday for a naval parade, killing all 10 crew members aboard, the country's navy said in a statement.

Naval officials said the incident occurred at the Lumut base in the western state of Perak on Tuesday morning.

"All victims were confirmed dead at the scene and sent to the Lumut base military hospital for identification," a spokesperson said.

A video circulating on local media showed several helicopters flying in formation, when one of the choppers' rotor clipped another before both aircraft crashed into the ground.

The navy said it would carry out an investigation.

Malaysian Defence Minister Mohamed Khaled Nordin said the aircraft - a maritime operations helicopter and a Fennec military chopper - were rehearsing for a parade celebrating the 90th anniversary of the Royal Malaysian Navy, due to be held on Saturday. (Reuters)