PARIS (AFP) - The top Catholic and Muslim clerics of the Central African Republic on Thursday asked the United Nations to immediately deploy peacekeepers to halt a spiral of violence that has pitted Muslims against Christians.

In an opinion column in France's Le Monde newspaper, the Archbishop of Bangui, Dieudonne Nzapalainga, and Imam Omar Kobine Layama, said French and African peacekeepers needed help to contain the violence.

"The UN must immediately dispatch such a force on the ground," they said.

France has sent 1,600 soldiers to its former colony to back an African Union peacekeeping force of about 4,000 troops. But they have been struggling to restore order in a country wracked by decades of misrule, coups and dictatorships.

To complicate matters, the large Chadian contingent of the AU force has been accused of siding with a mostly Muslim former rebel group in the strife-torn Christian majority country.

"Although the French and African forces have provided our country the opportunity to make a fresh start, the progress has been fragile and the troops cannot bear the burden themselves," they said.

They said the arrival of UN blue helmets "will eliminate the sentiment of fear and replace it with hope." The resource-rich but impoverished country has been wracked by ever-escalating violence since a March coup by the mostly Muslim Seleka rebels installed Michel Djotodia as the country's first Muslim president.

Although Djotodia disbanded the rebels, some of them went rogue, leading to months of killing, rape and pillaging and prompting Christians to form vigilante groups in response.

Nzapalainga and Layama said there was a real "threat that Muslims will face dreadful reprisals" following widespread rapes, looting and executions by the former rebels.

"We fear that if the international community does not respond more actively, our country will be condemned to darkness," they said, adding that two million people - or about half the country's population - were in desperate need of aid.