"Nine heroic soldiers fell as martyrs and four were injured in the accident," which occurred in the Bitlis province, the ministry said in a statement.

The ministry said the accident involved a Cougar helicopter but provided no details about the model.

The Cougar family of multi-purpose helicopters were developed by France and are now produced by Airbus.

The defence ministry said contact was lost with the helicopters 30 minutes after take off.

Its teams found the wreckage after launching a search with drones, a transport aircraft and a helicopter.

The ministry statement said a search on site "determined that the helicopter was damaged by an accident" but provided no other details.

It added that the injured were being transported to hospital.

Turkish forces have been conducting military operations against outlawed Kurdish militias across the southeast for years.

In 2017, a military helicopter crashed in the southeastern Sirnak province near Turkey's border with Syria and Iraq, killing 13 soldiers.