At least 60 people were killed late Monday when fighters from the Allied Democratic Forces (ADF), an ISIS affiliate, attacked a funeral in eastern Democratic Republic of Congo (DRC), local officials said.

Local administrator Macaire Sivikunula said 61 bodies had been recovered as of Wednesday. The U.S.-based SITE Intelligence Group, which monitors militant activity, reported the death toll could be closer to 100, though this claim has not been independently verified.

Sivikunula told Reuters the victims were “caught off guard at a mourning ceremony in the village of Ntoyo at around 9 p.m., and most of them were killed with machetes.”

The Congolese army said soldiers intervened but arrived after the killings.

The Islamic State’s Central Africa Province (ISCAP) later claimed responsibility for the attack. 

The ADF originated in Uganda in the 1990s and pledged allegiance to ISIS in 2017. It was designated a foreign terrorist organization by the U.S. in 2021.

Analysts estimate the group fields 1,000 to 1,500 fighters who rely on machetes, firearms, and improvised explosives.

The militia has carried out a string of massacres in eastern Congo this year, including an attack on a Catholic church in July that killed more than 30 worshippers.