Mr Sabiti Njiamoja, a deputy to the local governor, said on Monday Civilians were killed by fighters with the Allied Democratic Forces (ADF) believed to be linked with the Islamic State group in the Bambuba-kisiki area in Beni territory,.
Conflict has been simmering for decades in eastern Congo where more than 120 armed groups are fighting. Most are vying for land and control of mines with valuable minerals while some groups are trying to protect their communities.
Since last April, ADF attacks have killed at least 370 civilians and several hundred people have been abducted, including a significant number of children, according to the UN.
The group also extended its area of operations to Goma and into the neighboring Ituri province.