KABUL: At least nine people were killed when a military helicopter was shot down in central Afghanistan, President Ashraf Ghani said Thursday.

The ministry of defence said earlier the aircraft had crashed in a volatile district of Wardak province, where Afghan forces and local militias have fought bitterly in recent years. "Our helicopter was shot down... and our brave pilots were martyred," Ghani said at a ceremony at the presidential palace.

He did not say who was responsible, but warned "the perpetrators of the incident will be seriously punished".

The defence ministry said four crew and five security force members were killed.

Helicopter crashes are common in Afghanistan either due to technical problems or militant attacks.