KINSHASA, Congo (AP) — Armed fighters attacked a town in eastern Congo late at night, massacring at least 34 people including women and children who were at a local church, officials said Saturday.

Provincial interior minister Jean Julien Miruho said that the violence in Mutarule late Friday also left at least 27 others wounded.

Miruho said the identity of the assailants was unknown, though he believed the violence stemmed from livestock disputes in the area, about 40 miles (70 kilometers) from Bukavu.

“We cannot say exactly who these attackers were, but we will put together a commission of inquiry that will go to the site Sunday,” Miruho told The Associated Press. “It is clear that this attack was linked to the theft of cattle.”

Survivors blamed a rebel group from Burundi known as the FNL for the attack, though the claim couldn’t immediately be verified.

Eastern Congo is home to a myriad of armed groups and militias, many vying for control of the region’s vast mineral resources.

Many of the rebel groups sowing unrest there originate in other countries in the region, including Burundi, Uganda and Rwanda.

Congo’s military successfully sidelined one major rebel group — M23 — in eastern Congo last year with the help of a U.N. force with a stronger mandate.

Congo’s military is also working with a Rwandan Hutu militia group known as the FDLR to finally disarm after two decades of violence.

In Congo’s North Kivu province, Gen. Delphin Kahimbi said the government was giving the FDLR rebels a 30-day notice to voluntarily disarm. An estimated 1,400 FDLR fighters remain in eastern Congo, according to government estimates.