Congo has severed diplomatic ties with Rwanda as fighting between Rwanda-backed rebels and government forces rages around the key eastern city of Goma.

The three-year insurgency by the Rwanda-backed rebel group M23 has intensified, and the U.N. warned the violence could spill into a wider 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.

The M23 rebel group is advancing toward eastern Congo’s largest city of Goma. The United Nations says this has displaced over 178,000 people in the past two weeks.

Rwandan-backed fighters closed in on eastern Congo's largest city of Goma on Sunday (January 26), forcing thousands of civilians to flee and grounding flights from the local airport as government forces battled to stop the rebels seizing the city.

The Democratic Republic of Congo has severed diplomatic relations with Rwanda. This decision is due to the government in Kigali supporting rebels who are attacking Congolese government forces. At least 13 soldiers from international peacekeeping forces have lost their lives in the internal conflict.