BANGUI, Central African Republic (AFP) - Amnesty International said on Thursday the Central African Republic's mostly Muslim ex-rebels killed nearly 1,000 people in the capital Bangui two weeks ago in a rampage avenging deadly Christian militia attacks.

Communal violence exploded in Bangui after silently terrorising more remote parts of the country since a March coup made enemies out of Muslims and Christians who had long lived together in harmony.

European nations have offered assistance to help quell the violence, as French efforts to disarm fighters appeared to be paying off after the bloodshed earlier this month.

"The tension has eased considerably," said General Francisco Soriano, who heads the French troops in the impoverished country. "It's been rather calm in Bangui since Friday," he said. "Is it sustainable? I don't know."

A senior official with the African Union's peacekeeping force MISCA, said more than 7,000 fighters from the former Seleka rebel group which carried out the coup, had been disarmed in the past 10 days and were mostly staying in their barracks.

"We seem to be returning to a more normal situation," he said.

However the full extent of the violence that erupted in Bangui on Dec 5 began to emerge with an Amnesty International report based on a two-week fact-finding mission to the country.

The UN earlier estimated 450 people had been killed in Bangui and 150 elsewhere in the country.

The two-day spasm of violence began when Christian militias known as "anti-balaka" (anti-machete) went door-to-door in some districts in the capital "and killed approximately 60 Muslim men," Amnesty said in a statement.

"The de facto government forces, known as ex-Seleka, retaliated on a larger scale against Christians in the wake of the attack, killing nearly 1,000 men over a two-day period and systematically looting civilian homes. A small number of women and children were also killed."