The M23 rebel group has taken over the town of Nyanzale in eastern Democratic Republic of Congo, killing at least 15 people in bomb attacks, a local official said on Wednesday.

Nyanzale is about 130 km north by road from the provincial capital Goma, and is home to thousands of internally displaced people who fled fighting in surrounding areas.

"It is since the morning that we noticed the capture of Nyanzale by the M23, and the death toll rose to 15," said Isaac Kibira, a deputy to the governor in the nearby town of Bambo.

"The victims were killed by bombs fired indiscriminately by the M23," he told Reuters, adding that 10 people were killed in one house and other bodies found throughout the city.

M23 spokesperson Willy Ngoma wrote in a post on X late on Tuesday that Nyanzale was experiencing "tranquillity and deliverance," suggesting the group has gained control of it.

When asked whether the M23 had seized Nyanzale, Congolese army commander Jerome Chico Tshitambwe replied: "yes".

The M23 is a Tutsi-led group that has intensified its campaign in eastern Congo this year. UN experts and Western powers such as the United States and France say that the group is backed by Rwanda, which Rwanda denies.

The European Union this week called for dialogue between Congo and Rwanda in order to tackle the root causes of the conflict, saying only a political solution could end it.

"The strengthening of military capabilities as well as the use of surface-to-air missiles and sophisticated drones constitute a worrying escalation," the EU said.

Around 100,000 people have fled Nyanzale since the M23's advance in the last few days, said the UN humanitarian agency OCHA.