Ghana's army is investigating a deadly attack by gunmen on a military convoy that was escorting 140 civilians along a dangerous highway in the north-eastern of the country.

Seven gunmen and three civilians were killed in an exchange of gunfire in Binduri as the convoy was travelling between the centres of Bawku and Bolga. Ten suspects have been arrested.

A decades-long chieftaincy dispute has led to sporadic violence in the area with the Kusasi and Mamprusi ethnic groups claiming the traditional and powerful position.

Last year the government deployed extra soldiers to the area after some schools came under attack and the Asante king has led recent mediation efforts to restore calm.

Besides providing armed escorts, the government has been imposing curfews and joint military and police patrols to contain the violence.

The extra soldiers deployed are also tasked with securing the country's northern frontier with Burkina Faso, where armed Islamist militant groups are known to be active and are believed to sometimes cross the border.

The army said it had recovered a G3 automatic rifle, two full magazines and additional ammunition from one of the assailants who fled to a mosque to hide.

Operations to track down others linked to the attack are continuing.

The chieftaincy of Bawku used to rotate between the two groups, but several years ago the Supreme Court upheld the Kusasis' claim, fuelling further division.