Gunshots rang out Sunday night in the centre of the besieged Congolese city of Goma, AFP journalists heard, after the Democratic Republic of Congo accused Rwanda of sending fresh troops across the border to capture the strategic hub.

Congolese rebels and allied Rwandan forces entered the outskirts of Goma on Sunday and the airport in the key eastern city was no longer in use, the top UN official in the country said. Thousands fled the fighting that also killed at least 13 peacekeepers.

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.