Rebels seized the airport of east Congo's largest city, Goma, on Tuesday, potentially cutting off the main route for aid to reach hundreds of thousands of displaced people, after capturing the city in an offensive that left dead bodies lying in the streets.

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.

There was gunfire Tuesday in the eastern Democratic Republic of Congo city of Goma, as the United Nations warned of a worrying humanitarian situation amid clashes between Congolese soldiers and Rwandan-backed rebels who attacked the area and claimed to be in control.