The attack took place late on Saturday on two villages in Kanyola, an area some 50 km (30 miles) west of the provincial capital Bukavu, according to Radio Okapi, which broadcasts across the vast central African country.
A local civil society coordinator, Constantin Chahrondagwa, told Reuters many more people had been injured or kidnapped.
"Twenty-eight people were seriously injured and are at hospitals. Twelve were kidnapped and taken off into the forest, and of those three escaped," Chahrondagwa said by telephone after returning from the villages.
"They've just begun burying the dead. Everyone is traumatised. Everyone is afraid," he said.
The Congolese army and U.N. peacekeepers carried out joint operations several weeks ago in the area against fighters from the Democratic Forces for the Liberation of Rwanda, a Hutu-dominated Rwandan rebel movement based in eastern Congo.
Despite the official end of a 1998-2003 war, Congo's eastern provinces regularly witness violence at the hands of local militia, foreign rebel groups, and its own armed forces.
- Reuters - Thomson Reuters Foundation
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