Almost 500 fighters from a faction of one the largest armed groups in eastern Democratic Republic of Congo (DRC) have surrendered to the government just over a month after they attempted to overthrow the group's leader.

Soldiers from the NDC-R, a rebel group seen as having close ties with the national army, sang and danced before handing over an assortment of small arms at a ceremony on Monday in the village of Kashuga, about 75 km (46 miles) north of Goma.

Fighting has raged between two groups of the NDC-R since July 9 when a section loyal to deputy leader Gilbert Bwira Shuo attempted to oust their leader Shimiray Guidon, who is the target of UN sanctions, accusing him of human rights abuses.

"As you have just consented to become a government soldier, each of you come and lay down your weapon," Bwira told the group of fighters, who wore a hodge-podge of camouflage, European football shirts and rubber boots.

The surrender does not necessarily mean an end to their involvement in rebel fighting, said Christoph Vogel, a researcher at Ghent University in Belgium.

There was a big risk that the combatants might take up arms again after a year or two, he said.

"That's been happening many, many times across eastern Congo over the past 20 years," Vogel said.

Before the split, the NDC-R controlled vast areas of North Kivu province near the border of Rwanda and Uganda.

It earned money from the illicit gold trade and was frequently accused of being used by the army as a proxy force against other armed groups.

"Today we think it's time for us to surrender, lay down our arms and take part in the pacification of the country," said spokesperson Desire Ngabo Kisuba.

Kade Wabo, a Kashuga resident who watched the ceremony, said he remained wary of the group but was glad to see them lay down their weapons.

"They killed my son the day before yesterday," Wabo said. "But now we are very relieved."