Calls mount for Sri Lanka probe
Leading human rights group Amnesty International has called for an urgent inquiry into claims of civilian deaths in the last days of the Sri Lankan war.
Responding to a Times newspaper report that more than 20,000 were killed, it also urged the UN to publicise its estimate of the death toll.
UN human rights chief John Holmes said an investigation would be a good idea.
The Sri Lankan government has strongly denied the claims surrounding its recent onslaught against Tamil rebels.
The figures published on Friday in the Times newspaper in the UK - quoting official documents and witness accounts - is far higher than previously thought.
The UN says that there are no confirmed estimates of civilian casualties, and its last estimate two weeks before the end of the war said 6,500 people had died.
Claims of war crimes by both sides have arisen, including from Amnesty's Asia Pacific director Sam Zarifi.
"The Times report underscores the need for this investigation and the UN should do everything it can to determine the truth about the bloodbath that occurred in northeast Sri Lanka," he said.
Mr Holmes, the UN's senior humanitarian affairs co-ordinator, queried the figures but said the claims needed to be examined.
"I think a lot of the figures which are floating around don't have much justification behind them.
"But nevertheless, there have been serious charges against the [Tamil Tiger rebels]... for holding civilians as civilian shields for such a long time, and thereby being indirectly responsible for their deaths.
"And against the government for using heavy weapons in an area where there are so many civilians and thereby, not deliberately, but again causing many civilian deaths."
He added: "No-one was there, no-one knows and we may never know. And that's why an investigation would be a good idea."
Human rights lawyer Geoffrey Robertson QC says Sri Lanka will face an inquiry from the UN Human Rights Committee
Foreign journalists and humanitarian groups were barred from the conflict zone and although the Red Cross entered, it does not give evidence in international courts, he said.
"In the fullness of time, of course, you do have witnesses, you do have thousands of people who were on that dreadful strip of beach [designated as a safe zone by the government]."
He said as well as priests and doctors talking about what happened, there were also graves.
"This is the way, unfortunately, war crimes are now dealt with, through forensic investigators finding out the story by investigating mass graves.
"And there do seem, from aerial photographs, to be some."
A senior official from Sri Lanka's Centre for National Security told the BBC the accusations were totally false.
Video evidence published by The Times suggests that the Tamil Tigers established mortar positions and military encampments within camps for displaced people, which were then shelled by the military.
The paper says that it compiled its evidence using aerial photographs, official documents, witness accounts and expert testimony.