The United Nations has formally taken over a regional African peacekeeping mission in the Central African Republic, nine months after sectarian violence erupted which left at least 5,000 people dead and forced tens of thousands of Muslims to flee to neighbouring countries.

As the UN took over on Monday, about 1,800 additional peacekeepers and police joined the African Union's peacekeeping mission of 6,200 troops already in the country. 

Two-thousand French troops, deployed last December, will work alongside the new UN force.

Human rights groups say that the new force, when combined with the existing African troops, is still only about 65 percent of what was authorised by the UN Security Council in April.

They called for the full deployment of a nearly 12,000-strong force, which diplomats said would not take place until early 2015, the Associated Press news agency reported.

'Cosmetic change'

"The switch from AU to UN peacekeepers must be more than a cosmetic change: the swapping green berets for blue helmets. Instead it must serve as a fresh start for the peacekeeping operation in CAR," said Steve Cockburn, Amnesty International's campaigns deputy regional director for West and Central Africa.

The peacekeepers face the enormous task of bringing peace to one of the least developed countries on the African continent, with around 4.6 million people. In nearly two decades, 13 peacekeeping missions have been deployed to CAR, but none of them brought lasting stability.

The new reinforcements have come from Pakistan, Sri Lanka, Indonesia, Morocco and Bangladesh to join peacekeepers from other countries in Central Africa.

The UN has "worked tirelessly" since the April resolution was passed, said Stephane Dujarric, spokesperson for the UN Secretary-General, who emphasised that CAR is "an extremely, extremely complicated logistical situation" because it is land-locked with dilapidated roads that date back to independence from France in 1960.

"I think the last thing we have been doing is sitting on our hands, but we've been meeting logistical challenges... mobilising troops for a peacekeeping mission takes time," he said last week.

"We have to go knock on doors for troops, for equipment, helicopters and in the meantime I think we've been working very actively in the CAR, both on the political end and, of course, on the humanitarian end."

Civilians killed at 'alarming rate'

Mainly Muslim Seleka rebels seized power in March last year, which birthed a counter-offensive by Christian militias. Both sides deliberately targeted each other's civilian communities.

At least 5,204 people have been killed since the sectarian violence erupted last December, according to a tally compiled by AP. That figure is based on a count of bodies and numbers gathered from survivors, priests, imams and aid workers in more than 50 of the hardest-hit communities.

Civilians are still being killed "at an alarming rate," said Lewis Mudge, Africa researcher at Human Rights Watch who conducted a field mission this month on the ground.

"There is no time to lose," he said. "The new UN mission urgently needs to get more troops into eastern and central areas and take bold steps to protect civilians from these brutal attacks."

Meanwhile, the US announced that it would reopen its embassy in the capital city of Bangui. The US had suspended operations in Central African Republic and urged Americans to leave the country in December 2012 when violence erupted.

Secretary of State John Kerry said in a statement on Monday progress had been made at putting the nation on "a path toward peace and stability".

Source: Associated Press