The M23 rebel group is advancing towards another major city in the eastern Democratic Republic of the Congo, a leading UN official said on Friday.

Days after taking the key city of Goma, the Rwandan-backed fighters are about 60 kilometres north of Bukavu, said UN peacekeeping expert Jean-Pierre Lacroix.

Bukavu, the capital of South Kivu province, is home to hundreds of thousands.

M23 rebels are also moving towards a major airport north of the city, which would be a significant step, Lacroix said.

A spokesman said the United Nations is moving staff out of Bukavu as a precautionary measure.

M23 is one of more than 100 armed groups in resource-rich eastern Congo and has conflicted with government troops for years.

M23 leader Corneille Nangaa said Thursday that the group is “in Goma to stay” and announced a march on the capital, Kinshasa, to overthrow President Félix Tshisekedi.

While Rwanda denies backing the rebels, the UN has repeatedly called on Kigali to withdraw its forces from Congo and end its support for M23.

The global body said at least 700 people have been killed in the latest clashes since Sunday.

The fighting also left 2,800 people injured and the numbers are expected to rise as more information emerges, UN spokesman Stéphane Dujarric said late on Friday.

The worsening conflict in eastern Congo is causing a human rights crisis, the UN human rights office warned earlier on Friday, amid reports of an escalation of sexual violence.

The Geneva-based agency–formally known as the Office of the United Nations High Commissioner for Human Rights– said it received reports from the provincial capital Goma and combat zones in the neighbouring province of South Kivu of mass rape.

“We are verifying reports that 52 women were raped by Congolese troops in South Kivu, including alleged reports of gang rape,” the office said in a statement, noting that such violence was nothing new.

“Conflict-related sexual violence has been an appalling feature of armed conflict in eastern DRC for decades,” the OHCHR said.

Fighting has intensified in the region in recent days since the M23 rebel group claimed control of Goma on Lake Kivu.

In the territories it has captured, M23 has “occupied schools and hospitals,” driven out displaced residents, and “subjected the civilian population to forced conscription and forced labour,” the UN said.

(dpa/NAN)