UN envoys urged African countries Wednesday to reinforce a military mission struggling to contain strife that some officials have warned could become genocide.
Only 4,000 troops of a promised 6,000 African force have been deployed while France now have 1,600 soldiers in the country, mainly in the capital Bangui.
But on a day in which at least 10 people were killed in lynchings and other sectarian attacks in the capital, UN envoys on genocide prevention, human rights, children and sexual violence in conflict all called on the UN Security Council to order tougher action.
Adama Dieng, the UN adviser on the prevention of genocide, said the size of the African force officially known as MISCA means it cannot cope with the chaos.
"There is an urgent need for the full deployment of MISCA peacekeepers as soon as possible," Dieng told a Security Council meeting on the conflict that erupted in March when rebels overthrew the president.
Dieng said that on a visit to the country in December, he had been shocked by the "level of hatred" that has built up between the Muslim and Christian populations as the government has lost control.
He said there was a "high risk both of crimes against humanity and of genocide."
Leila Zerrougui, UN envoy on children in conflict, estimated that there are up to 6,000 child soldiers in the various militias battling for control of the country of 4.5 million people.
She also said there were some 500,000 children among the more than 900,000 people who have fled their homes because of the strife.
Between January and November 2013, more than 4,500 cases of sexual violence by fighters in the Seleka coalition of rebels were recorded, according to Zainab Bangura, the UN special representative on sexual violence in conflict.
"I am here today to plead for your continued attention to this crisis," Zerrougui told the 15-member council, which faces calls from France for the UN to take over the African force.
She said there had been "unprecedented levels of brutality" in attacks on children and others.
"We need to send a stronger signal to perpetrators of these atrocious crimes that they will be held to account," she said.
UN leader Ban Ki-moon named Bernard Acho Muna, a Cameroon Supreme Court lawyer and former deputy chief prosecutor of the International Criminal Court for Rwanda, to lead a commission of inquiry for Central African Republic ordered by the Security Council.
Ex-Mexican foreign secretary Jorge Castaneda and Fatimata M'Baye, a lawyer and leading Mauritanian human rights activist, will also serve on the commission that has a mandate to identify perpetrators of rights crimes.