Troops clashed with M23 rebels around a strategic highway in eastern Democratic Republic of Congo on Thursday, sources said, following a recent flare-up between the two sides.
A mostly Congolese Tutsi group, the M23 resumed fighting in 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 group's resurgence has destabilised regional relations in central Africa, with the DRC accusing its smaller neighbour Rwanda of backing the militia.
The frontline between Congolese troops and M23 rebels had been calm in recent weeks until Thursday, when clashes erupted again.
On Sunday, M23 fighters captured the village of Ntamugenga in North Kivu's Rutshuru area, according to local officials.
The village lies about four kilometres (2.5 miles) from the RN2, a strategic highway leading to the provincial capital Goma.
Fighting between soldiers and the M23 spread to the highway itself on Thursday.
"Clashes are ongoing on the RN2," said local official Justin Komayombi, who added that the road was blocked because M23 fighters were in the settlements of Kako and Kalengera.
Samson Rukira, a local civil-society leader in Rutshuru, confirmed the road had been blocked. "The situation is tense," he said.
The Kivu Security Tracker (KST), a respected violence monitor, also said that M23 activity had cut access to a portion of the highway.
The militia is occupying the settlements of Rubare, Kalengera and Kako, it added, which all lie on the highway.
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 one of the 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Despite official denials from Kigali, an unpublished report for the United Nations seen by AFP in August pointed to Rwandan involvement with the M23.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 same report said the M23 plans to capture Goma, an important trade hub of about one million people, in order to extract political concessions from the Congolese government.