Fresh clashes between the army and M23 rebels have erupted in eastern DR Congo, officials said on Sunday, breaking a period of relative calm between the two sides.

A mostly Congolese Tutsi group, the M23 resumed fighting late 2021 after lying dormant for years. It has since captured swathes of territory in North Kivu province, including the strategic town of Bunagana on the Ugandan border in June.

The resurgence of the group has destabilised regional relations in central Africa, with the Democratic Republic of Congo accusing its smaller neighbour Rwanda of backing the militia.

The frontline between Congolese troops and M23 rebels had been calm in recent weeks. But clashes erupted again on Thursday, violence monitor Kivu Security Tracker stated on Saturday evening.

On Sunday, army officials and residents said that M23 fighters had captured the village of Ntamugenga, a strategic target that lies close to the highway leading north out of provincial capital Goma.

"The situation is gloomy here," said village chief Celestin Nyamugira, explaining that M23 fighters had erected a barrier at the entrance to the settlement. "They came from the forest and infiltrated the city."

Congolese Colonel Mavinga Serge confirmed the capture of the village to AFP, but said troops were "next door".

Another officer, Lieutenant Colonel Ndjike Kaiko, said the army was "containing" the rebels.

Doctors Without Borders (MSF) tweeted that 500 people had taken refuge in a convent in Ntamugenga, including some who were wounded, and urged the creation of a humanitarian corridor to evacuate civilians.

The M23 first leapt to prominence in 2012 when it briefly captured Goma before a joint Congolese-UN offensive drove it out.

The militia is just one of scores of armed groups that roam eastern DRC, many of them a legacy of two regional wars that flared late last century.

Despite official denials from Kigali, an unpublished report for the United Nations seen by AFP in August pointed to Rwandan involvement with the M23.

The official death toll from the latest clashes remains unclear. Kivu Security Tracker said at least two civilians had been killed and a dozen wounded in recent clashes.

Medical officials from the region's Rutshuru Hospital said that four civilians had been killed on Friday and Saturday, with eight wounded.

On Sunday, the head of Ntamugenga hospital John Sebatware said that five soldiers and one civilian had been killed, with 33 people wounded.