The UN's refugee agency said Tuesday it was prepared to help evacuate some 19,000 Muslims at risk of attack from mainly Christian militias in the conflict-torn Central African Republic.

"What we don't want is to stand by and watch people being slaughtered," UNHCR spokeswoman Fatoumata Lejeune-Kaba told reporters in Geneva.

She pointed out that so-called anti-balaka militias controlled major routes to and from Bangui as well as a number of towns and villages in the southwestern part of the country.

They posed a particular threat to Muslims in the PK12 neighbourhood of the capital, in Boda, Carnot and Berberati to the west and Bossangoa further north, she said, lamenting that "we fear for the lives of 19,000 Muslims in those locations".

"UNHCR stands ready to assist with their evacuation to safer areas within or outside of the country," she said, pointing out that so far "the only thing keeping them from being killed right now is the presence of (international) troops".

UN staff were heading to the town of Bemal in the north Tuesday to discuss possibly relocating Muslims there, but Lejeune-Kaba said it was difficult, since locals feared welcoming evacuees could attract unrest to their area.

The chronically unstable Central African Republic sank into chaos after the mainly Muslim Seleka rebels who had helped topple president Francois Bozize a year ago refused to lay down their arms and went rogue.

Their campaign of killing, raping and looting prompted members of the Christian majority to form the anti-balaka vigilante groups, which are also accused of atrocities.

Around 8,000 international troops are working to contain the crisis in the former French colony, where more than 2,000 people have been killed since December.

At the height of the crisis in December and January, more than a quarter of the country's 4.6 million people had fled their homes.

A new surge in bloodshed has forced nearly 16,000 people from their homes in the capital since early last week alone, Lejeune-Kaba said.

According to UNHCR numbers, 637,000 people in total are now displaced inside the country, including 207,000 in Bangui, while 82,000 mostly Muslim Central Africans had streamed into neighbouring countries in the past three months.

The increase in violence has claimed more than 60 lives in the capital since March 22, Cecile Pouilly, spokeswoman for the UN's human rights office, told reporters Tuesday.

She pointed especially to a grenade attack on a funeral service in Bangui that claimed at least 20 lives on March 27, and to the 24 people killed on Saturday by Chadian soldiers.

"It appears that Chadian soldiers fired indiscriminately at a crowd following an incident," she said, stressing that her office was "still trying to confirm the exact affiliation of these soldiers".

Pouilly also said she expected a UN team of investigators on the ground in the country to probe allegations that Chadian soldiers supporting the Seleka have been targetting Christians.