Human rights campaigners on Tuesday accused Sri Lanka of whitewashing military abuses in its official report on the island's decades-long ethnic war, which ended in May 2009. A defence ministry report released on Monday admitted for the first time that civilians may have been killed during the war, though the military followed a "zero civilian casualty policy." Brad Adams, Asia director of Human Rights Watch, said the report was a "feeble attempt" to convince the world the military had not committed war crimes. "The Sri Lankan government is finally admitting that its forces caused civilian losses during the conflict’s final months, but unconvincingly claims no responsibility," Adams said. "This is just the latest and glossiest effort to whitewash mounting evidence of government atrocities during the fighting." While the report detailed the numerous abuses over the years by the Tamil Tiger rebels, it provided no serious discussion of alleged war crimes by Sri Lankan forces, the New York-based Human Rights Watch said. "The report describes the Tamil Tigers’ use of 'human shields,' shootings of civilians seeking to escape Tamil Tiger-controlled areas and other abuses, but it ignores the Sri Lankan military’s role in civilian deaths," the rights group said. Senior Sri Lankan military officials had privately admitted civilian casualties, but Monday's report was the first acknowledgement of them in an official document. The report gave no estimates for the number of civilian casualties. The United Nations and rights groups have said that the number could be as high as 40,000. Defence Secretary Gotabhaya Rajapakse said claims of high civilian casualties were "vague accusations" designed to tarnish the image of the country. The UN has said there were credible allegations that security forces carried out executions, killed civilians and deprived civilians trapped in the war zone of basic food and medication. Colombo has denied the allegations.