Democratic Republic of Congo's M23 rebels are moving south towards Bukavu, the capital of South Kivu province, in what appears to be an attempt to expand their area of control in the country's east after capturing the city of Goma.

Rwanda-backed M23 rebels faced pockets of resistance from army and pro-government militia overnight after entering eastern Congo's largest city Goma in the worst escalation of a conflict that has run for more than a decade.

Congolese forces were losing control of the key city of Gom a on Wednesday after rebel groups backed by Rwanda took over the airport and shared plans to set up a new administration. Soldiers fighting for Congo - many of them mercenaries from other nations - were laying down their weapons at the border with Rwanda.