Six people including civilians were killed when security forces in northern Burkina Faso were ambushed by militants.

A soldier and five civilians from the Volunteers for the Defence of the Fatherland (VDP) were killed in the attack.

"The Kourao VDP were patrolling the area and were targeted by armed individuals. A unit went to their aid and came under heavy fire," the AFP news agency quoted a security source as saying on Sunday.

The civilian volunteers are part of a network that helps the army in fighting militant groups operating in Burkina Faso.

The VDP was formed more than a year ago to bolster efforts by vigilante groups operating in the volatile northern and eastern regions.