Rwanda-backed rebels entered the outskirts of eastern Congo’s largest city, Goma, on Sunday, causing what the United Nations called “mass panic” among its 2 million people and leading Congo’s government to call it a “declaration of war.

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.

Explosions and gunshots were heard in city - home to more than a million people - late on Sunday evening, according to local media reports. A spokesman for rebel group has told the Reuters news agency its forces will seize control of Goma at 03:00 local time (01:00 GMT).