* Britain questions whether Sri Lanka should get IMF loan
* U.N. chief, Miliband decry civilian deaths
* Russia, China, others avoid meeting on Sri Lanka (Adds Ban, paragraph 4, Kouchner, paragraphs 9-10, rights group, paragraph 16-17)
By Louis Charbonneau
UNITED NATIONS, May 11 (Reuters) - Britain's foreign minister and the U.N. chief said on Monday they were appalled by reports that hundreds of Sri Lankan civilians were killed over the weekend in what the United Nations called a "blood bath."
British Foreign Secretary David Miliband also raised doubts about whether Colombo could be trusted to use a $1.9 billion loan from the International Monetary Fund appropriately.
"I am appalled by reports that came out of Sri Lanka over the weekend of mass civilian casualties," he told reporters ahead of a U.N. Security Council meeting on unrelated matters.
U.N. Secretary-General Ban Ki-moon issued a statement through his spokeswoman saying that he, too, was appalled.
In the latest and largest reported assault on civilians trapped in the war zone, hundreds of people were reported killed on Sunday and Monday in artillery barrages that struck the narrow strip of territory that separatist rebels control.
A U.N. spokesman in Sri Lanka said more than 100 children were killed in the "blood bath" as the government tries to wipe out the last remnants of Tamil Tiger rebels.
The stakes could not be higher for either Sri Lanka, which does not want its impending victory in the 25-year war snatched away, or the Tigers, who have vowed no surrender despite facing overwhelming numbers, force and odds.
Miliband and French Foreign Minister Bernard Kouchner hosted a meeting on Monday of concerned U.N. delegations and non-governmental organizations (NGOs) active on the ground.
'A WAR WITHOUT WITNESS'
"Our message is a simple one, which is that the killing must stop," Miliband said. "The civilians ... trapped in the zone, up to 50,000 in an area of just 3 square kilometers (1.6 square miles) are the victims of what at the moment is a war without witness."
After the meeting with NGOs, Miliband said that he and Kouchner would raise the alleged use of heavy artillery by government forces in the conflict zone with Colombo "as a matter of the utmost urgency."
"It goes directly contrary to the commitments that were made to Foreign Minister Kouchner and I when we were in Sri Lanka," Miliband said.
The 10 council members who attended the meeting, a diplomat said, heard of the difficulties aid organizations were having getting access to refugees and the camps where they are held.
Diplomats on the 15-nation Security Council say that China, Russia, Vietnam, Japan and several other members oppose formal council discussion of Sri Lanka, arguing that it is an internal matter for the Sri Lankan government. Miliband disagreed.
"We believe very, very strongly that the civilian situation in the northeast of Sri Lanka merits the attention of the United Nations at all levels," he said.
Kouchner and Austrian Foreign Minister Michael Spindelegger echoed Miliband.
Council members China, Vietnam, Russia, Burkina Faso and Libya did not attend the meeting with NGOs, diplomats said.
"If the Security Council stays silent on this issue any longer, it will be a failure of historic proportions," Steve Crawshaw of Human Rights Watch, one of the groups that met with the council, told Reuters. "It is already late, but lives can still be saved."
U.S. officials said last month they wanted to delay a $1.9 billion IMF loan that Sri Lanka is hoping to get to pressure the government to do more to help the civilians trapped in the conflict zone. Miliband indicated that he supported this view.
"It's essential that any government is able to show that it will use any IMF money in a responsible and appropriate way, and ... I don't think that's yet the case," he said. (Editing by Will Dunham)
Security personnel stand guard at the entrance of the sealed-off Guomen Hotel in Beijing May 12, 2009. Chinese health authorities are searching for around 150 people who took the same flights ...
China
