The UN has said widespread shelling by the Sri Lankan government killed most of the tens of thousands of civilians who died in the final months of the 25-year-long war in 2009. The report also accuses Tamil Tiger separatists of using civilians as human shields. The UN is calling for an independent investigation into what it says could constitute war crimes. The government has consistently denied claims it targeted civilians. Sri Lanka had asked the UN not to publish the report, saying it could damage reconciliation efforts. It has rejected the findings as biased and fraudulent. The report paints a brutal image of the final offensive on the Tamil enclave in northern Sri Lanka between January and May 2009. It said that hospitals, UN centres and ships belonging to aid group the Red Cross were deliberately shelled by government forces.