(Reuters) -Congolese authorities have blocked access to the airport in Goma, a provincial capital in eastern Democratic Republic of Congo, and cancelled flights as Rwandan-backed rebels advance on the city,

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

Fighting with M23 rebels in eastern Democratic Republic of Congo left six United Nations peacekeepers dead, UN officials said Saturday.

Congolese troops pushed back an attempted overnight advance by Rwanda-backed rebels on the eastern city of Goma, two Congolese army sources said on Saturday, after the sound of nearby heavy bombardment rocked the city in the early hours.

Civilians in eastern Democratic Republic of Congo are at increasing risk as the abusive M23 armed group, supported by the Rwanda Defence Force (RDF), approaches Goma, the capital of North Kivu province.

Fighting has escalated sharply in recent weeks in eastern Congo, where rebels have seized key towns and are closing in on the city of Goma, the government’s last stronghold in the North Kivu province,

Panic spread in Goma on Thursday, with M23 rebels steadily inching closer to the city in eastern Congo as they battle the Congolese army. Bombs were heard going off in the distant outskirts and hundreds of wounded civilians were brought in to the main hospital from nearby towns and villages.

M23 has made significant territorial gains in recent weeks, encircling Goma, which has around two million people and is a regional hub for security and humanitarian efforts. View on euronews