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.

Congolese troops with support from Burundi's army appeared on Friday to be holding back a push south by Rwandan-backed rebels seeking to expand their grip on eastern Congo in a weeks-old advance that has raised fears of a broader regional conflict.

The Tutsi-led rebels have seized Goma, the largest city in east Congo and capital of North Kivu province, which is home to lucrative gold, coltan and tin mines. They then moved on towards Bukavu in South Kivu province,

Rwandan-backed M23 rebels in Democratic Republic of Congo are seeking to advance south towards Bukavu, the capital of South Kivu province, in an attempt to expand their area of control in the country's east after capturing the city of Goma.

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.

By Sonia Rolley (Reuters) -When M23 rebels swept into the Congolese city of Goma this week, world powers urged them to immediately withdraw. Instead, the Rwanda-backed insurgents are intent on showing they can restore order and govern.