The world will probably never find out how many innocent civilians died during the bloody final phase of Sri Lanka's war against Tamil Tigers rebels, the UN humanitarian chief said. The United Nations believes that anywhere from 80,000 to 100,000 people died in what was one of Asia's longest modern wars, erupting in earnest in 1983 when Tamil Tiger rebels began to fight for a separate state for Sri Lanka's minority Tamils. UN under-secretary-general John Holmes, who oversees the United Nations' many humanitarian operations, told reporters that it was unclear how many died in the months before Sri Lanka declared victory over the LTTE on May 18. Holmes said the initial figure of 7,000 deaths had been deemed far too questionable for official publication. Those were “estimates based on the best evidence that we had, but that wasn't very good evidence because we weren't really present in the (battle zone) in any systematic way,” Holmes said. “That's why we didn't publish them.” No evidence of mass graves He said there would likely never be a reliable death toll. “I fear we may (never know), because I don't know that the government would be prepared to cooperate with any inquiry,” Holmes said. But there was no doubt “several thousand” civilians had died during the siege, he added. During that siege, Holmes repeatedly criticized the government for shelling areas where civilians were trapped, warning that it could lead to a “bloodbath”. He also criticized the LTTE for treating innocent civilians as hostages. The UN Human Rights Council decided this week not to investigate the civilian deaths in the war, a decision that human rights groups have described as disappointing. British media reports also said that aerial photographs taken when a UN delegation flew over the former conflict zone last week showed evidence of mass graves. While in actual, photos of those locations showed no clear signs of mass graves, though some individual gravesites might be visible. Holmes said the appearance of makeshift cemeteries was no surprise. “A lot of people were killed, several thousand, so you would expect to see a lot of graves there,” he said.