Rebels occupying the eastern Democratic Republic of Congo city of Goma have declared a cease-fire but the government dismissed the pause in the fighting as a ruse aimed to head off growing international concern.

Fighting last week between government forces in the Democratic Republic of the Congo and Rwanda-backed rebels in the major eastern city of Goma left at least 900 people dead, the UN health agency has said.

The Rwanda-backed rebels who seized a major city in eastern Congo have declared a unilateral ceasefire, citing humanitarian grounds. But, there was no sign of them giving up control of Goma at the heart of a region home to trillions of dollars in mineral wealth.

Rwanda-backed rebels claimed on Monday they captured eastern Congo’s strategic city of Goma, the hub of a region containing trillions of dollars in mineral wealth that remains largely untapped.

Over 2,000 bodies require burial in Goma after Rwanda-backed M23 rebels took over the Democratic of Congo city last week, inflaming a decade-old conflict and humanitarian crisis, Congo's communications minister Patrick Muyaya said late on Monday.

Bodies are lying on the streets. Medical staff in overwhelmed hospitals are treating hundreds of wounded civilians against the backdrop of gunfire and mortar fire.

Rebel groups, including the M23 rebels, have declared a humanitarian ceasefire in the Democratic Republic of Congo. At least 900 have been killed and nearly 3,000 others injured in recent fighting around the city of Goma,