At least 10 crew members were on board the aircraft, say local media reports.
BBC SPORT
Two navy helicopters collided in mid-air during a rehearsal for a Royal Malaysian Navy celebration event.
At least 10 crew members were on board the two aircraft, say local media reports.
The reports suggest that there have been casualties, but this has not been officially confirmed.
One of the choppers clipped the rotor of the other before the two crashed into the ground at a stadium, according to footage published on local media.
The BBC is seeking information from Malaysian authorities.
