During a practice for a party of the Royal Malaysian Navy, two army helicopters collided in midair.
At least 10 squad members were on board the two plane, say regional media reports.
The studies suggest that there have been deaths, but this has not been formally confirmed.
According to footage that was released on local advertising, one of the aircrafts clipped the wheel of the other before the two crashed into the earth at a venue.
The BBC is seeking knowledge from Malaysian officials.