Nearly three thousand people have been killed in the city of Goma in the eastern Democratic Republic of Congo, according to the United Nations, after the provincial capital was captured by rebels following days of fierce fighting with the Congolese army.

The rebels continued advances in eastern Congo despite their own announcement of a cease-fire. The U.N. secretary-general called for them to lay down their guns and agree to mediation.

Congolese troops have fought back against Rwanda-backed rebels who the U.N. says are moving fast into the South Kivu province after seizing the region’s largest city and an international airport