Ten soldiers and a gendarme in northern Burkina Faso were killed on Friday in an attack by unidentified gunmen on a military post, the army said.

Attacks in Burkina Faso were rare before a major strike by al Qaeda-linked fighters on a hotel in the capital Ouagadougou killed 29 people in January.

Islamic militants are active in Burkina Faso’s northern neighbor Mali and Burkinabe authorities are concerned the long desert border between the two countries could become a transit point for militants.

Friday’s attack about 30 km (19 miles) from the Malian border began at around 5 a.m. (0500 GMT) and was carried out “by about 40 heavily armed individuals who have not yet been identified,” the army said in a statement.

A newly-formed militant group led by a fighter formerly loyal to Algeria’s Mokhtar Belmokhtar claimed to have attacked a Burkinabe military position in September and unidentified gunmen killed three Burkinabe soldiers and two civilians in October.

(Reporting By Mathieu Bonkoungou; Writing by Aaron Ross; Editing by Matthew Mpoke Bigg/Jeremy Gaunt)