Authorities confirmed 773 bodies and 2,880 injured persons in Goma's morgues and hospitals, Congolese government spokesperson Patrick Muyaya told a briefing in the capital, Kinshasa, adding that the death toll could be higher.

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.

The U.N. health agency says that fighting last week between Congolese government forces and Rwanda-backed rebels in the major eastern city of Goma left at least 900 people dead, raising the previously cited death toll of 773.

The Democratic Republic of Congo’s government says the Rwanda-backed rebels’ advance constitutes a “declaration of war."

Hundreds of wounded people have poured into overcrowded hospitals in Goma after Rwanda-backed rebels captured the major city in eastern Congo last week.