Democratic Republic of Congo President Felix Tshisekedi has vowed “a vigorous and coordinated response” against a rebel alliance that has besieged swaths of the nation’s mineral-rich east and forced hundreds of local troops and foreign mercenaries to surrender.

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.

Desperation, looting and bodies in the streets are being reported in Goma, after Rwanda-backed M23 rebels claimed to have captured the Congolese city. It's the latest move after years of fighting in the country's mineral-rich east.