"Active zones of combat have spread to all quarters of the city, all the neighborhoods of the city," Lemarquis, the deputy U.N. envoy and top U.N. aid official in the DRC, told reporters in New York via video from Kinshasa.

Artillery fire and gunshots echoed across the major hub in the DRC's mineral-rich east, as Kigali said five civilians were killed across the Rwandan border.

Heavy artillery fire rocked the eastern Congolese city of Goma on Monday as France warned the capital of the mineral-rich region was on the brink of falling to militia fighters and Rwandan troops. Repeated explosions from heavy artillery and intense bursts of gunfire echoed across central Goma on Monday,