The Codeco militia group on Sunday executed 17 people it had captured in the Djugu territory, in eastern Democratic Republic of Congo.
The victims were passengers aboard four vehicles heading to Mungwalu, in Ituri province, UN-sponsored Radio Okapi reported.
They were taken hostage after three Codeco members were killed in a clash with a rival militia, the radio added.
Among those taken hostage was a pregnant woman, AFP news agency reported.
Local authorities are yet to comment on the attack.
The Codeco, a militia that claims to protect the Lendu farming community in Ituri, is one of myriad armed groups operating in the restive, mineral-rich region.