* Pre-positioned troops start arriving in Bangui
* Residents welcome French deployment but abuses continue
* Toll from week seen well over 200 dead (Writes through with UN, Red Cross comment)
By Emmanuel Braun and Paul-Marin Ngoupana
BANGUI, Dec 6 (Reuters) - France rushed troops to Central African Republic on Friday, its second major African intervention in a year, but clashes between Muslim and Christian militias continued unabated, spilling into widespread killings of civilians.
"This horrific cycle of violence and retaliation must stop immediately," a United Nations spokesperson said, citing cases of rival Seleka and "anti-balaka" militias raiding homes and killing adults and children. "Civilians must be protected."
The Red Cross said it had collected 281 bodies from two days of fighting in Bangui, but many more had been killed.
In Paris, French President Francois Hollande told a meeting of African leaders that the CAR crisis proved the urgent need for the continent to create its own regional security force.
"Africa must be the master of its own destiny and that means mastering its own security," he said. Paris was ready to train 20,000 African soldiers a year and provide staff for the force's command structure.
Hundreds of soldiers started arriving in CAR from neighbouring countries, hours after Paris was given a U.N. green light for the mission to restore order.
Joanna Mariner, part of an Amnesty International team in Bangui, said that she had reports of pillaging and killing in the 3rd district. "The French are patrolling on the main axes, but the city isn't yet secure," she added.
A Reuters correspondent saw 26 bodies in the streets and in court yards of houses in the 1st district, close to the centre of Bangui.
Officials at Bangui's Hopital Communutaire said wounded people had been streaming in all day. Dozens of bodies had been delivered to the morgue, which was now so full that corpses were being stored in other parts of the hospital.
An aid worker in Bossangoa, about 300 km north of the capital, said at least 30 people had been killed there.
The former French colony has slipped into chaos since mainly Muslim Seleka rebels seized power in March, leading to tit-for-tat violence with "anti-Balaka" militia formed by the Christian majority. The violence that began on Thursday was the worst the capital has seen during the crisis.
France, which halted an advance by al Qaeda-linked rebels on the Malian capital Bamako this year, began assembling a new 1,200-strong force for CAR just hours after winning U.N. backing. The operation was codenamed Sangaris, after a red butterfly found in the country.
"We are grateful to France but it's not normal that it's forced to intervene to save us, like a fireman, 50 years after independence," Guinean President Alpha Conde told the Paris conference, urging the creation of an African 'NATO'.
"What's happening in Bangui, coming so soon after Mali, should make us all reflect and I hope that here we will ... give ourselves the means to resolve conflicts in Africa."
Earlier this year, France launched a huge operation to dislodge al Qaeda-linked fighters from northern Mali. But Paris is keen to distance itself from the system of 'Francafrique' where, for decades after independence, it supported authoritarian regimes in return for business contracts.
Despite the French intervention, Friday saw renewed and fighting between Seleka Muslim former rebels now in charge of the country and a mix of local Christian militiamen and other fighters loyal to ousted president Francois Bozize.
Central African Republic is rich in gold, diamonds and uranium but decades of instability and spillover from conflicts in its larger neighbours have kept it mired in crisis.
A resident in the PK12 neighbourhood said Seleka fighters were "going door-to-door". "They are looting and they are killing people. They are calling everyone "anti-balaka"," he said, asking not to be named for his own safety.
Foreign Minister Laurent Fabius said French forces would initially focus on securing Bangui and roads leading to Chad and Cameroon. They would also deploy with African forces to other towns including Bossangoa, where an African peacekeeper was killed after coming under attack by Seleka.
Highlighting the extent of the challenge facing French forces, the aid worker in Bossangoa, where tens of thousands of people, mainly Christians have fled their homes, said fighting between communities continued there on Friday.
Dieudonne Yanfeibona, a priest at the mainly Catholic mission said: "Seleka are now burning down the neighbourhood all around. There's a risk that they will commit a massacre."
Michel Djotodia, leader of the Seleka ex-rebel alliance, is CAR's interim president, but he has struggled to control his loose band of fighters, many from neighbouring Chad and Sudan.
Asked whether Djotodia was legitimate and should remain in power, Fabius said he had taken power "in a debatable way" but added: "I think we don't need more difficulties by adding the departure of the president." He said, however, that elections should begin by early 2015 at the latest. (Additional reporting by Mark John and John Irish in Paris; Michelle Nichols at the United Nations and Joe Bavier in Abidjan; Writing by David Lewis; Editing by Ralph Boulton)