KINSHASA, Congo — Gunmen have killed at least six rangers in Virunga National Park, the latest attack in the part of eastern Congo that is home to some of the world’s last mountain gorillas, officials said.

The violence took place on Sunday in Nyamitwitwi, located in the Rutshuru area of the park, said Olivier Mukisya, spokesman for the Congolese Institute for the Conservation of Nature.

“We confirm that a group of armed men attacked our positions,” Mukisya told The Associated Press. “We have dead and wounded among our ranger colleagues.”

There was no immediate claim of responsibility, though past attacks on Virunga park rangers have been blamed on several armed groups that vie for control of eastern Congo’s natural resources. Among those rebel groups is the Democratic Forces for the Liberation of Rwanda, known by its French acronym FDLR, an ethnic Hutu group opposed to the government of neighboring Rwanda and one of the last factions of Rwandan rebels active in the Congo.

In April 2020, an ambush near the Virunga National Park killed 12 rangers and five civilians, and critically injured several others.

More than 200 rangers have been killed since Virunga became a national park in 1925, officials say.