More than 100 armed Rwandan rebels from a group linked to the country's 1994 genocide have surrendered in Democratic Republic of Congo.

The United Nations mission in DRC (MONUSCO) welcomed Friday's move, but cautioned it would take time to see if the rebel movement was serious about disarming.

"For the first day, this is a good start, but more can be done," General Abdallah Wafi, from MONUSCO, told the AFP news agency.

"We are encouraging the process and have mobilised all our [military and logistic] resources but only coming days will tell us if the process is credible and serious," he added.

The rebels are members of the Democratic Forces for the Liberation of Rwanda (FDLR), which includes remnants of the militia that carried out the genocide of at least 800,000 ethnic Tutsis, according to the UN, and which is now based in DRC.

Choice for rebels

The 105 men surrendered with their weapons on Friday at a grammar school in Kateku, about 220 kilometres north of Goma, capital of North Kivu province.

Nord-Kivu governor Julien Paluku said the surrender was the first step in a process which should be wound up "within 22 days", with the ex-rebels given a choice to return to Rwanda or ask for political asylum.

Of the 105 rebels, MONUSCO eventually only transferred 97 to Kanyabayonga, south of Kateku. "Some disappeared as soon as they were to climb onto [MONUSCO] trucks," said Wafi.

The FDLR has around 1,500 men, according to UN estimates, or 4,000, according to Kigali. They are scattered across Kivu province, where they have been accused of widespread violence and rights abuses.

The group's armed wing promised to lay down arms in late 2013 but the Rwandan government has refused to hold talks.

The DRC and Rwanda have for years accused each other of using the FDLR for their own interests.