* Hundreds of thousands have fled conflict in CAR
* UN refugee agency details grisly inter-communal violence
* Under-reported as not seen as having wider repercussions
By Tom Miles
GENEVA, April 16 (Reuters) - Inter-communal violence is tearing Central African Republic apart but the conflict is not getting the attention, or aid, needed to save huge numbers of lives, the head of the U.N. refugee agency (UNHCR) said on Wednesday.
Almost 200,000 people have fled the country since December, and a further 160,000 are expected to this year. The UNHCR says it is spending cash there three times as fast as new funds are coming in, putting its mission in jeopardy.
"Indeed, we are in trouble," UNHCR chief Antonio Guterres told diplomats as he launched a $274 million appeal.
Central African Republic is only one crisis among many demanding U.N. funds stretched by humanitarian needs in South Sudan, Somalia and Yemen, as well as natural disasters such as Typhoon Haiyan in the Philippines, and above all, Syria.
"Obviously there's no way we'll to be able to sustain this until the end of the year," Guterres told the diplomats. "At a certain moment we will be simply broke."
Central African Republic's government fell a year ago to Muslim Seleka rebels who were routed in December by Christian militia forces, unleashing anarchy and ethnic cleansing.
"When you start cutting people into pieces and roasting them," Guterres told reporters, "It's not an army against an army - it's people doing horrible things to their neighbours."
But the crisis has no major economic or strategic repercussions beyond the country's immediate neighbours, he said, so it gets little attention from the outside world.
"People do not feel threatened. People feel threatened with Syria, people feel threatened with Ukraine and what might happen. Even Somalia. But in relation to the Central African Republic people don't feel threatened, don't know where it is, it's very difficult, they've never heard about it."
Diplomats at the meeting were effusive in their support but only Japan's ambassador pledged actual financial aid, and even he admitted to being not well informed on the subject.
"What I heard today is much more dramatic than I had imagined before I came to this chamber," Ambassador Takashi Okada said.
The U.N. appeal included a gallery of photographs of wounded and malnourished refugees arriving in Cameroon, but the official chairing the meeting said they were too "heart-wrenching" to inflict on the diplomats, who were invited to stay behind afterwards if they wanted to view them. About half left.
Although the U.N. Security Council last week authorised the creation of a nearly 12,000-strong U.N. peacekeeping force, it is not due to be in place until mid-September.
William Lacy Swing, head of the International Organization for Migration and a former U.S. ambassador to Central African Republic, said the country could not wait, and the current French and African Union forces were not big enough.
"The number 1 priority is to stop the fighting. You will not arrive at that without the (U.N.) blue helmets," said Swing. "Unfortunately September's a long time away. A lot of people are going to die before that force can be assembled and deployed."
The first priority had to be to secure the capital Bangui, creating "zones of peace" to bring people out of 70 or more "spontaneous settlements around town where people are hunkered down hoping to avoid being killed", he said. (Editing by Stephanie Nebehay and Robin Pomeroy)