No less than 12 soldiers were reportedly killed and 27 others injured when extremist militants staged an attack against an army base and an adjacent town in central Mali on Tuesday.

The tragic attack featured the intense firing on troop positions, burning buildings and pillaging shops, officials said.

“They attacked the city and the army posts, plundered stores, burned public buildings and then left,” army spokesman Souleymane Maiga told Reuters.

The official said the assailants had briefly taken control of the military base in Nampala, in semi-desert scrubland close to the Mauritanian border, and that Malian troops had then retreated to nearby Diabaly to regroup.

A separate Malian intelligence source told Reuters that, after briefly seizing the base, the militants retreated into a forest with weapons and vehicles they had seized.

Awash with guns and home to a plethora of rival armed groups nursing various local grievances, Mali has seen a surge in violence since a 2015 peace agreement, which has failed to prevent violence between different ethnic factions.

French forces intervened in the vast desert country in 2013 to drive back extremist fighters who had hijacked a Tuareg uprising in 2012 to take over the desert north.

But despite 11,000 U.N. peacekeepers deployed since, militants have reorganized and continue to launch attacks across Mali and its neighbors.There was confusion over who was behind Tuesday’s attack.

Authorities blamed extremist militants, but a donor-funded national radio station, Studio Tamani, said it had received a phone call from a new militia allegedly defending the Peul Muslim ethnic group.

The station said the call came from The National Alliance for the Safeguarding of Peul Identity and the Restoration of Justice (ANSIPRJ), headed by Oumar Aldjana.

If confirmed, it would be the first time the group, which was set up last month and includes some who fought alongside the extremists, has launched an attack.