Picture used for illustration.

Terrorist armed with guns and rocket-propelled grenades killed six soldiers in an ambush in northeast Nigeria on Sunday, security sources said.

The terrorist group attacked a patrol outside Tungushe, a village 22 kilometres (13 miles) from the Borno State capital Maiduguri, they said Monday.

"Two patrol vans came under fire from the terrorists and the leading vehicle was hit by an RPG, killing six soldiers on board," a security source said Monday.

Three of the terrorists were killed in a battle with soldiers following the ambush, a second security source said.

The Tungushe area has been repeatedly targeted by militants. The insurgents attack troops and raid villages for food and livestock.

In October a soldier and three civilians were killed when militants attacked troops in Tungushe.

The decade-long insurgency in northeast Nigeria has killed 35,000 people and displaced around two million people.

The conflict has spilled into neighbouring Niger, Chad and Cameroon, prompting a regional military coalition to fight the terrorist groups.

Agence France-Presse