Two Malaysian navy helicopters collided in mid-air during a rehearsal for a naval parade on Tuesday, leaving ten dead as all crew members on board died.

The incident occurred at the Lumut naval base, in the western state of Perak, after 9:30 a.m., the Malaysian navy said in a statement. “All victims are confirmed dead at the scene and sent to the Lumut Naval Base Military Hospital for identification.” Seven of the victims were crew members of the Maritime Operations Helicopter, while the remaining three were aboard the Fennec.

A video that circulated in local media and on social networks shows the moment in which several helicopters fly in formation and one of them with its rotor collided with another before both ended up crashing to the ground. Local police confirmed that the images were true.

Defense Minister Mohamed Khaled Nordin explained that the planes – a maritime operations helicopter and a Fennec military helicopter – were rehearsing for the Royal Malaysian Navy’s 90th anniversary parade, which will be held on Saturday. At the same time, Khaled assured that efforts are being made to verify the identities of the murdered crew members, all of whom were under 40 years of age.

The incident comes just eight months after a small plane crashed on a highway in Malaysia’s Selangor state, leaving ten people dead. Malaysian Prime Minister Anwar Ibrahim published a message on his social networks in which he states that the nation is mourning the “devastating tragedy” and assures that the Ministry of Defense has launched an investigation into what happened.