Several homes were also torched in the town of Misia on Wednesday, Kwilu province interior minister Jean-Claude Bwanganga told AFP.
"Sixteen people were killed and 25 others are missing", he said, adding that soldiers and police had been despatched to "hunt down these enemies".
Misia is near the town of Kwamouth, where fighting between the Yaka and Teke people has been raging since June.
The conflict has left more than 180 people dead, according to the DRC government, and the UN says tens of thousands have been displaced.
"Among the 16 people killed was the leader of a group" of villages, civil society leader Placide Mukwa said, explaining that attackers in nearby forests regularly target settlements.
Eighteen people were killed in clashes between the Yaka and Teke in August, according to a government report seen by AFP.
RHM/PR