Sri Lanka war crimes probe call
Twenty-four local rights groups signed a memorandum to the UN Human Rights Council saying they believe the government is not sincerely investigating the allegations.
The call coincides U N Human Rights Council session in Geneva where member countries will review Sri Lanka's progress in investigating abuses. The council has passed two previous resolutions asking Sri Lanka to conduct its own probe.
The United States has said it will sponsor a third resolution at the current session on Sri Lanka's lack of progress.
UN human rights chief Navi Pillay in her report to the council has recommended an international investigation. Sri Lanka's government however has rejected the call.
Government forces defeated separatist Tamil Tiger rebels in 2009, ending a quarter-century civil war. Both sides have been accused of war crimes and serious human rights violations.
Sri Lankan troops have been accused of deliberately shelling civilians, hospitals and blocking food and medicine for the people in the war zone as a war tactic.
The Tamil Tigers are accused of holding civilians as human shields, killing those trying to escape and recruiting child soldiers.
A previous UN report said as many as 40,000 ethnic Tamil civilians may have been killed in just the last five months of the fighting.