The death toll from an attack in a village in eastern Democratic Republic of Congo’s Ituri province rose to 25 on Sunday, a local chief and civil society leader said, after a government spokesman and a U.N. document confirmed the attack on Saturday.

The Cooperative for the Development of the Congo (CODECO) group, one of many militias operating in the conflict-ridden east, carried out the killings in the village of Galayi, 70 km (45 miles) northwest of the city of Bunia, they said.

Fifteen bodies were discovered on Sunday, in addition to 10 bodies recovered on Saturday, Banzala Danny, a local chief, and Vital Tungulo, a civil society leader, told Reuters.

An internal U.N. document seen by Reuters, and Jules Ngongo, spokesperson for the governor of Ituri province, both confirmed the attack and the initial death toll of 10 civilians.

“We assure that all the killers will be punished by justice,” Ngongo said.

The human rights situation in Ituri has deteriorated since the beginning of the year as CODECO carries out more attacks, the United Nations Joint Human Rights Office (UNJHRO) said in a report published in March.

CODECO and the Allied Democratic Forces (ADF), another militia group, are responsible for most civilian killings in eastern DRC, according to a report by the U.N. peackeeping mission released in March.