Fighting erupted Friday between M23 militiamen and government troops near the eastern DR Congo city of Goma, sources said, hours before the expected arrival of a European mercy flight.
The aid mission is the first in an airlift announced last Saturday by the European Union to help the beleaguered city.
After a day of relative calm, clashes took place early Friday near the village of Murambi, less than 30 kilometres (18 miles) west of Goma, local officials said.
Murambi is the last settlement before the town of Sake, considered the city's last bulwark.
"The population is starting to panic again," Leopold Busanga, a spokesman for civil society groups in Sake.
Fighting was also reported further north, around 70 kms (43 miles) from Goma, an official there said.
Goma, the capital of North Kivu province, has been under threat since the M23 launched an offensive last year after reviving from dormancy in 2021.
Its advance has triggered tension in central Africa.
The Democratic Republic of Congo accuses its neighbour Rwanda of supporting the group, something that Kigali denies, and regional countries have deployed a joint force aimed at stabilising the region.
Independent UN experts, the United States and several other western countries agree that Rwanda is backing the M23.
Goma, a trading hub of more than a million people that has also seen an influx of thousands of displaced people, lies on the shore of Lake Kivu.
Most of the land routes to the city have now been cut off, leaving flights the only reliable way to bring in supplies. The EU plane is carrying emergency shelters, medication and hygiene kits.
The M23, whose name stands for the March 23 Movement, is one of scores of armed groups that roam eastern DR Congo, many of them a legacy of two regional wars that flared at the end of the 20th century.
In 2012, the Tutsi-led group briefly captured Goma before a joint Congolese-UN offensive drove it out.
Eastern Democratic Republic of Congo. By Nalini LEPETIT-CHELLA (AFP)
In recent months, several ceasefires have been attempted, the latest of which was supposed to have taken effect on Tuesday.
But all have failed, and the M23 is continuing to advance.
A United Nations Security Council delegation arrived in DR Congo late Thursday for a three-day visit to assess the situation in Goma.
The team will meet President Felix Tshisekedi and fly to the city on Saturday.