At Least 36 people were killed by extremists in conflict-riddled eastern Congo, the military said on Thursday.

The Allied Democratic Forces, a rebel militia with links to the Islamic State group, killed civilians in Mukondi village in North Kivu province, said Congo army spokesman in Beni town, Capt. Anthony Mwalushayi.

“The enemy made the incursion into the chiefdom of Bashu and managed to kill 36 of our compatriots and burned some residents’ huts in the area,” he said. Several people were injured in Wednesday night’s attack and an investigation has been launched to search for the missing, he said.

The conflict has been simmering in eastern Congo for decades as more than 120 armed groups fight for power, influence and resources, and some to protect their communities. The ADF has been largely active in North Kivu province but has recently extended its operations into neighboring Ituri province and to areas near the regional capital, Goma.