Residents of the besieged city of Goma, in the east of the Democratic Republic of Congo, say they are gripped by fear as gunshots continue to ring out around their homes, days after rebel forces claimed they had taken over.

Rwanda-backed rebels claimed on Monday they captured eastern Congo’s strategic city of Goma, the hub of a region containing trillions of dollars in mineral wealth that remains largely untapped.

Bodies are lying on the streets. Medical staff in overwhelmed hospitals are treating hundreds of wounded civilians against the backdrop of gunfire and mortar fire.

Rwanda-backed rebels claimed they captured eastern Congo’s strategic city of Goma, the hub of a region containing trillions of dollars in mineral wealth that remains largely untapped, the Associated Press reported.

M23 rebels claim they now control the Congolese city of Goma—an act Congo's government described as a 'declaration of war.'

A rebel alliance spearheaded by the ethnic Tutsi-led M23 militia said it had seized the lakeside city of more than 2 million people.

U.S. Secretary of State Marco Rubio called for a urgent cease-fire in the conflict in eastern Democratic Republic of Congo saying Washington was "deeply troubled" by a recent escalation in the fighting.

Our peacekeepers are also planning on sending out patrols today in Goma to assess the situation, to conduct resupplies and assess routes in the capital,' says spokesman - Anadolu Ajansı

Rwandan forces are present in Goma backing up M23, according to Congo and U.N. sources, while Burundian forces have been sent to beef up Congo's defences in South Kivu. Rwanda has not commented directly on its troops' presence on Congolese soil.

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 Rwanda Defense Force reported escorting hundreds of "Romanian mercenaries" out of the Democratic Republic of the Congo after seizing Goma.