The Rwanda-backed rebels who seized eastern Congo’s key city of Goma have announced a unilateral ceasefire in the region for humanitarian reasons, following calls for a safe corridor for aid and hundreds of thousands of displaced people.

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.

M23 rebels in the Democratic Republic of Congo said they would begin a unilateral ceasefire on Tuesday as the Group of Seven nations demanded that the Rwanda-backed militia halt an offensive that has shaken the eastern part of the country.

Rwanda-backed rebels who have captured eastern Congo’s largest city say they plan to take their rebellion to the capital and seek to gain political power.

The city of 2 million people is at the heart of a region home to trillions of dollars in mineral wealth and remains in rebel control.

Congolese forces were losing control of the city of Goma on Wednesday after rebel groups backed by Rwanda took over the airport and shared plans to set up a new administration.

The group called the Congo River Alliance also includes the Rwanda- backed M23 rebels, who were reported to be gaining territory in other eastern parts of the country while advancing on South Kivu's provincial capital,