Two Malaysian navy helicopters collided in mid-air during a rehearsal for a naval parade on Tuesday, killing all 10 crew members aboard, the navy said in a statement.
The incident occurred at the Lumut naval base in the western state of Perak at 9.32 a.m. on Tuesday morning (0132 GMT), the navy said.
"All victims were confirmed dead at the scene and sent to the Lumut naval base military hospital for identification," the navy 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. Local police confirmed the footage was genuine.
The navy said it would carry out an investigation into the cause of the accident.
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.
Efforts were underway to verify the identities of the crew members killed, all of whom were below the age of 40, Mohamed Khaled told reporters.
Israeli planes and tanks pounded areas across the Gaza Strip overnight and on Sunday, destroying several residential buildings, witnesses said, as Palestinians desperately awaited implementation of a US plan to end the war.
The number of students confirmed dead after the collapse of a boarding school building in Indonesia rose to 36, from 16 a day earlier, the country's disaster mitigation agency said on Sunday.
Russia rained missiles and drones on Ukraine in a mass overnight attack, officials said on Sunday, killing at least five people and damaging civilian infrastructure including energy facilities across numerous regions.
Heavy rains triggered landslides and flash floods blocking roads, washing away bridges and killing at least 47 people since Friday in Nepal, officials said on Sunday.