Two military helicopters collided in mid-air before crashing and killing all 10 people on board during a flight rehearsal in Malaysia this morning.

The choppers were among seven that had taken off simultaneously from the Royal Malaysian Navy (TLDM) Base in Lumut, Perak, shortly after 9am local time to practice for the Navy fleet's open day celebrations in May.

Disaster struck when two helicopters strayed too close to one another as they flew in low formation over a stadium. 

The rotors of one aircraft appeared to clip the tail of the second, sending both aircraft hurtling to the ground in deadly tailspins.

Shocking footage showed how the aircraft plummeted to the ground after the brutal collision, as Navy personnel standing on the parade square below looked on in horror. 

The footage shows how two of the touched rotors at a height of around 200ft

Shocking footage showed how the aircraft plummeted to the ground after the brutal collision, as Navy personnel standing on the parade square below looked on in horror

The choppers were among seven that had taken off simultaneously from the the Royal Malaysian Navy (TLDM) Base in Lumut, Perak, Tuesday, April 23

The two helicopters involved in the collision were HOM and Fennec models. The HOM helicopter was carrying four crew and three passengers, while the Fennec was carrying three crew

Two military helicopters collided in mid-air before crashing and killing at least 10 people in Malaysia this morning

One of the helicopters careened onto a running track and burst into flames, with photos showing the Eurocopter AS555SN Fennec heavily mangled and surrounded by rescue personnel. 

The other helicopter, an AgustaWestland AW139, is understood to have come down on the edge of the stadium where the TLDM had planned to host its 90th anniversary celebrations.

Prime Minister Anwar Ibrahim sent his condolences to the families of the victims, saying 'the nation mourns the heart-wrenching and soul-wrenching tragedy'.

'I was informed that an immediate investigation will be carried out by the Ministry of Defense, especially TLDM, to find the cause of the crash,' he said.

Incidents involving helicopters are not uncommon in the Southeast Asian nation.

Last month, a Malaysian coast guard helicopter crashed in the Strait of Malacca with no fatalities.

In 2016, a deputy minister was among those who died after a Eurocopter AS350 crashed in the Malaysian state of Sarawak.

Today's fatal crash comes just days after two Japanese navy helicopters carrying eight crew members crashed in the Pacific Ocean south of Tokyo during a night-time training flight.

One crew member who was recovered from the water was later pronounced dead, while rescuers continue their search for seven others who are still missing.

The two SH-60K aircraft from the Maritime Self-Defence Force were carrying four crew each and lost contact near Torishima island, about 370 miles south of Tokyo, late on Saturday, Defence Minister Minoru Kihara told reporters.

The cause of the crash was not immediately known, but officials believe it is 'highly likely' the two helicopters collided with each other before crashing into the water, Mr Kihara said.

He added that his ministry will suspend training flights for all SH-60s for now.

The navy chief of staff, Admiral Ryo Sakai, said the training will be suspended until the cause of the accident cause is determined and preventive measures are adopted.

The two SH-60K aircraft from the Maritime Self-Defence Force were carrying four crew each and lost contact near Torishima island, about 370 miles south of Tokyo

One crew member who was recovered from the water was later pronounced dead, while rescuers were searching for seven others who were still missing

Rescuers have recovered a flight data recorder, a blade from each helicopter, and fragments believed to be from both aircraft in the same area, signs that the two SH-60Ks were flying close to each other, Mr Kihara said.

Officials will analyse the flight data to try to determine what led to the crash.

Search and rescue efforts for the missing crew were expanded on Sunday, with the MSDF and Air Self-Defence Force together deploying 12 warships and seven aircraft. Japan Coast Guard patrol boats and aircraft also joined the operation.

The helicopters, twin-engine, multi-mission aircraft developed by Sikorsky and known as Seahawks, were modified and produced in Japan by Mitsubishi Heavy Industries. They were on night-time anti-submarine training, Mr Kihara said.

One lost contact at 10.38pm local time and sent an automatic emergency signal a minute later. They lost contact about 150 nautical miles (270km) east of Torishima island.

Only one distress call was heard - another sign that the two helicopters were near the same place, because their signals use the same frequency and could not be differentiated, Mr Kihara said.

One helicopter belonged to an air base in Nagasaki, and the other to a base in Tokushima prefecture.