Colombo, Aug 31 : UN High Commissioner for Human Rights Navi Pillay hit back at Sri Lankan government critics for calling her a tool of the Tamil Tigers at the conclusion of her mission in Colombo Saturday.

Pillay said the claims were both "wildly inaccurate" and "deeply offensive", Xinhua reported.

The UN envoy said the abuse against her on the basis of her Indian Tamil descent has reached an extraordinary crescendo during her visit to assess the country's human rights situation four years after the end of the war with separatist rebels.

"At least three government ministers joined in," Pillay told reporters here.

Pillay said Sri Lankan President Mahinda Rajapaksa had apologised to her for the statements made by his ministers.

Pillay said calls for an independent international inquiry would likely continue unless there is a credible national process to address allegations of civilian casualties and summary executions during the war.

"Appointing the army to investigate itself does not inspire confidence in a country where so many past investigations have foundered," the UN envoy said.

Pillay had visited the north and east of Sri Lanka, including former Tamil Tiger rebels-held areas and met families of those who went missing during the war.

She welcomed investigations launched by the government over the missing in the north and east.(IANS)