COLOMBO: Human rights groups in Sri Lanka are asking the UN to set up an international investigation of alleged war crimes and other rights violations during the country's civil war.

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.

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.

The US has said it will sponsor a resolution at the Human Rights Council on Sri Lanka's lack of progress in investigating the allegations.