( CNN ) -- A United Nations panel investigating alleged war crimes in the Sri Lankan conflict has found credible evidence that the military shelled civilians in no-fire zones and sought to silence critics in brutal fashion , according to the panel 's report , leaked to a Sri Lankan newspaper . The report contradicts claims by the Sri Lankan government that it adopted a policy of `` zero civilian casualties '' in the final stages of its bloody 25-year battle with the Tamil rebels . `` The government shelled on a large scale in three consecutive no-fire zones , where it had encouraged the civilian population to concentrate , even after indicating that it would cease the use of heavy weapons , '' according to the report , published last week on the website of the newspaper , The Island . `` It shelled the United Nations hub , food distribution lines and near the International Committee of the Red Cross ships that were coming to pick up the wounded and their relatives from the beaches . It shelled in spite of its knowledge of the impact . ... Most civilian casualties in the final phases of the war were caused by government shelling . '' The Sri Lankan government denounced the report as `` fundamentally flawed . '' A statement from the Ministry of External Affairs said that `` among other deficiencies , the report is based on patently biased material , which is presented without any verification . '' President Mahinda Rajapaksa has said he will turn a planned May Day rally into a protest against the United Nations . U.N. officials would not comment on the leaked report , but spokesman Farhan Haq said the published portions are accurate . `` They are incomplete , they 're certainly not the full report , but they are accurate renditions of things that appear in the text , '' he said . U.N. Secretary-General Ban Ki-moon appointed the three-member panel last year to advise him on accountability issues relating to alleged human rights violations during the final stages of the Sri Lankan war , which ended in May 2009 . The panel found both sides accountable for serious war crimes . The report says the Liberation Tigers of Tamil Eelam , who fought fiercely to secure an independent state for minority Tamils , `` refused civilians permission to leave , using them as hostages , at times even using their presence as a strategic human buffer between themselves and the advancing Sri Lanka army . `` All of this was done in a quest to pursue a war that was clearly lost ; many civilians were sacrificed on the altar of the LTTE cause and its efforts to preserve its senior leadership , '' the report says . The government , the report says , `` systematically shelled hospitals on the frontlines . '' It also `` systematically deprived people in the conflict zone of humanitarian aid , in the form of food and medical supplies , particularly surgical supplies , adding to their suffering . To this end , it purposely underestimated the number of civilians who remained in the conflict zone . Tens of thousands lost their lives from January to May 2009 , many of whom died anonymously in the carnage of the final few days . '' The report also is critical of government soldiers ' screening of civilians in their hunt for rebels . Sometimes , it says , those who were singled out as suspects were summarily executed . `` If proven , those most responsible , including Sri Lanka Army commanders and senior government officials , as well as military and civilian LTTE leaders , would bear criminal liability for international crimes , '' the report says . Sri Lanka 's long and bloody conflict devastated nearly two-thirds of the population in its northern and eastern provinces . As many as 70,000 people were killed .
The panel finds that the military shelled civilians in no-fire zones . The government denounces the report , which was leaked to a newspaper . The report says both the government and the rebels committed war crimes . The government fought a long and bloody battle with the Tamil Tigers .