* Up to 1.3 million people identified as "food insecure"
* Crisis caused by Christian-Muslim militia violence
* WFP chief says it is difficult to distribute food
* MSF criticises "unacceptable performance" of U.N. agencies
By Pascal Fletcher
JOHANNESBURG, Dec 16 (Reuters) - Up to a quarter of the population of Central African Republic risks going hungry because of fighting between Christian and Muslim militia, and this number could increase, the chief of the U.N. World Food Programme said on Monday.
WFP Executive Director Ertharin Cousin told Reuters that security in the capital Bangui, which has seen a wave of killings and reprisals in the last two weeks, and in the rest of the country was still not guaranteed despite the presence of 1,600 French troops and an African peacekeeping force.
This was making it difficult for humanitarian agencies to distribute food and other supplies to over half a million people who have fled their homes since mainly Muslim Seleka rebels took power in March, ousting President Francois Bozize.
Christian defence groups have sprung up since then.
An assault on Bangui earlier this month by these Christian militia, aided by gunmen loyal to ousted President Bozize, sparked waves of tit-for-tat attacks that killed over 500 people and displaced some 160,000 in the capital alone, according to figures cited by the WFP chief.
"Every area is different, some days an area that was accessible the day before is no longer accessible," Cousin said in an interview in Johannesburg after attending the burial of South Africa's anti-apartheid hero Nelson Mandela on Sunday.
She said a quarter of Central African Republic's 5.2 million population was now identified as "food insecure" following the upsurge in violence and killings since Dec. 5.
"We now estimate that there are approximately 1.1 to 1.3 million who are in danger of going hungry and our goal is to ensure that we reach all of them and that we consistently reach them over the next six months," Cousin said.
This figure was likely to rise in the coming months.
"Because the farmers haven't been able to access their farms, we've missed this year's planting season, so that when we get to the harvest in the spring, this (threat of hunger) will probably be even more exacerbated," Cousin said.
U.N. AGENCIES FACE CRITICISM
She said the WFP had been escalating its food distribution to respond to the increased emergency since Dec. 5. "Do we need to do more? Yes, we do," she added.
Last week, the international medical charity Medecins Sans Frontieres (MSF) sharply criticised U.N. humanitarian agencies for what it called their "unacceptable performance" in addressing the needs of victims in Central African Republic.
"MSF deplores the appalling performance of U.N. humanitarian agencies and reminds them of their responsibility to mobilise and coordinate effective and principled humanitarian action," the charity said in a Dec. 12 open letter sent to the U.N.'s top humanitarian coordinator, Valerie Amos.
Responding to this criticism, Cousin said: "Do we need to scale up? Yes. Is there enough criticism that we can spread around? Of course."
"But what we need to do instead of criticising each other is to ensure that we are performing the work, that we are communicating with all the partners so that everyone is aware of what we are doing and we are identifying the opportunities to do more," she added.
Cousin said the French troops deployed this month to try to stop the violence in Central African Republic had managed to restore some order, but only up to a point.
"What they're doing is they're providing access into certain areas, they can't be everywhere," she said.
Michel Djotodia, in charge of the former French colony since the Seleka rebels took over in March, dismissed three members of his government this weekend following the wave of Muslim-Christian clashes.
He is weighing a possible amnesty for militias involved in the violence. (Editing by Pravin Char)