Blasts killed at least nine people Friday in a displaced persons camp on the outskirts of Goma in the war-torn eastern Democratic Republic of Congo, local sources said.

"Bombs" fell on huts housing displaced people, according to witnesses, in the central African country's eastern region, which has seen ongoing fighting between M23 (March 23 movement) rebels and the government.

After eight years of dormancy, the mostly Tutsi M23 rebellion took up arms again in late 2021, seizing large swathes of North Kivu province, some forty kilometres (25 miles) northwest of its provincial capital Goma.

The origin of Friday's blasts has not been clearly established. According to witnesses, government forces positioned near the camp had been bombarding the rebels on the hills further west since early morning and, according to a civil society activist, "the M23 retaliated by throwing bombs indiscriminately".

Government spokesman Patrick Muyaya accused "the Rwandan army and its M23 terrorist supporters" of being responsible on X.

"Horror in its most serious form! A bomb on civilians, deaths, children! A new war crime," he wrote.

According to Kinshasa, the United Nations and Western countries, neighbouring Rwanda is backing the M23, something Kigali denies.

"I saw nine bodies in front of me" including several children, Dedesi Mitima head of the Lac Vert neighbourhood to the west of Goma, told AFP. Another official gave a provisional death toll of 10.

A hospital source said on condition of anonymity: "We have just received 32 wounded and four bodies."

The huts were either side of the road leading from Goma to the strategic town of Sake, about 20 kilometres from the capital.

Fighting intensified around Sake early February and the rebels have since seized new towns in Masisi district, northwest of Goma, including the mining town Rubaya.

The UN estimated at the end of 2023 that nearly seven million people had been displaced in DR Congo, including 2.5 million in North Kivu alone.