Ten crew members have been killed after two Malaysian Navy helicopters met a tragic fate on Tuesday after they collided mid-air, and later crashed to the ground, Al Jazeera reported.

In a statement, the Royal Malaysian Navy said that the two aircraft collided on Tuesday morning as they were taking part in aerial training in northern Lumut, where the navy has its headquarters.

One helicopter, an Agusta Westland AW139 Maritime Operations Helicopter (HOM), crashed onto the steps of the stadium at the complex while the second, a Eurocopter Fennec, fell near a swimming pool, as per Al Jazeera.

According to the navy, there were three crew members aboard the Eurocopter and seven on the Agusta. At the site of the crash, the deaths of all crew members were confirmed.

The incident took place when the helicopter crews were practicing for next week’s Navy Day celebrations which start on May 3.

The Malaysian armed forces will form an investigation board to probe the helicopter collision. Armed Forces Chief Mohammad Ab Rahman extended his condolences to the victims’ families.

Defence Minister Mohamed Khaled Nordin is expected to visit the crash site. Malaysian Prime Minister Anwar Ibrahim described the collision as a “heart-wrenching tragedy” and confirmed that an investigation would take place.