Johannesburg — At least 60 people were killed in an attack by machete-wielding members of an ISIS-affiliated rebel group in Eastern Congo on Monday night, local officials said Tuesday. The attack was the latest by the Allied Democratic Forces in a region where a range of armed groups have preyed upon an impoverished population as they vie for control of huge rare mineral reserves.

The attack happened in the evening as a group of people attended a funeral in the town of Nyoto, Macaire Sivikunula, a local administrator in North Kivu province’s Lubero territory, told the Reuters news agency.

“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,” he said, adding that a search for the attackers was ongoing.

“The ADF attack caused around 60 deaths, but the final toll will be given later this evening because the territory has just deployed services to the area to count the number of beheaded people,” Colonel Alain Kiwewa, another local administrator in the Lubero territory, was quoted as saying by The Associated Press.

“There were about 10 of them. I saw machetes. They told people to gather in one place and started cutting them. I listened to people screaming and I fainted,” a survivor told an AP journalist at a burial service on Tuesday.

Samuel Kagheni, a local civil society leader, told Reuters the assailants used machetes and also shot some victims before setting fire to vehicles.

The ADF started off in neighboring Uganda in the mid-1990s as an Islamist militia, before moving into the border region with the Democratic Republic of Congo. The militia established ties with ISIS in 2018 and was designated by the U.S. State Department as a foreign terrorist organization in 2021.

The U.S. government cited brutal violence committed against both civilians as well as regional military forces in making its designation. Experts believe the ADF likely has somewhere between 1,000 and 2,000 members,  including some foreign fighters.

Monday’s attack was the latest in a series of recent killings in the region. Two ADF attacks last month left 52 people dead, including eight women and two children, according to regional officials.

Bintou Keita, head of the United Nations mission in Congo known as MONUSCO, said in a statement last month that the “attacks targeting civilians… are intolerable and constitute serious violations of international humanitarian law and human rights.”

In response to last month’s attacks, MONUSCO said it had reinforced its military positions in the region.

There are more than 120 armed militias operating in Eastern Congo, and the ADF is one of the largest and most brutal.

President Donald Trump has waded into the ongoing regional crisis, trying to broker a peace deal between Congo and neighboring Rwanda, which is believed to back the M23 rebel group that launched a major offensive into Eastern Congo earlier this year, seizing two large cities as well as mineral mines. The deal has not been finalized.