KINSHASA: Two military helicopters crashed in a strife-torn part of eastern Democratic Republic of Congo with at least four crew members on board, authorities said on Monday.

Government spokesman Lambert Mende told Reuters it was not clear what brought down the helicopters on Friday in North Kivu province near the borders with Rwanda and Uganda.

Over the weekend, UN-sponsored Radio Okapi cited military sources as saying that the helicopters crashed while pursuing fighters from the former Congolese rebel group M23. An army spokesman declined to comment.