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

Rwandan-backed M23 rebels asserted their control over east Congo's largest city Goma on Thursday by calling on residents to resume normal life, even as the group clashed with Congolese troops as they tried to take more territory.

There has been fierce fighting as Rwanda-backed M23 rebels advance towards the second-largest city in eastern Democratic Republic of Congo, marking a further escalation in the region's conflict. M23 fighters have been moving south, towards Bukavu, the capital of South Kivu, after capturing the largest city in the region, Goma.

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.

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,

Rwanda-backed rebels were expanding their presence in eastern Congo after capturing Goma, the region's major city, the U.N. said Friday, also expressing concerns over executions it learned were carried out by the rebels in recent days following a major escalation of their yearslong rebellion.

M23 rebels, with support from Rwandan troops, marched into Goma earlier this week and are now advancing south toward Bukavu.