A militia killed at least 23 people in attacks on several villages in eastern Democratic Republic of Congo's Ituri province in recent days, local authorities said on Saturday.

The Cooperative for the Development of the Congo (CODECO) group, one of many armed groups operating in the conflict-ridden east, carried out the killings in Djugu territory on Thursday and Friday, two local community leaders told Reuters.

"Most of the victims were killed with machetes, but those who tried to flee were shot. In all these villages, people's belongings were taken, houses were burnt down," said Vital Tungulo, president of Djugu's Nyali-Kilo community.

The motive for the attacks was not clear but militia violence in Congo is linked to long-running competition for influence and the region's rich mineral resources.

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.

The army spokesperon in Ituri, Jules Ngongo Tshikudi, confirmed the attacks, describing them as unacceptable.

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

It was not possible to reach CODECO for comment on the latest attacks.

Local resident and community leader Daniel Anikumu said they had started burying those killed, including the burial of 11 people in a mass grave in the village of Gangala.