United Nations chief Antonio Guterres on Sunday urged Rwanda to withdraw its forces from the eastern Democratic Republic of Congo where fierce fighting raged as Kigali-backed fighters closed in on the major city of Goma.

Rebels in Democratic Republic of Congo are closing in on a key city in the mineral-rich region aided by neighboring Rwanda’s army, the head of a peacekeeping mission told United Nations Security Council members during an emergency meeting on Sunday.

Rwanda-backed rebels have 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. Analysts said the M23 fighters aimed to control the city of about 2 million people and perhaps other areas in the region nearly 1,