By Ranga Sirilal and Shihar Aneez
COLOMBO, March 26 (Reuters) - An international inquiry into alleged Sri Lankan war crimes would allow witnesses to testify after domestic probes failed to carry out credible investigations, the U.N. human rights chief said on Wednesday, on the eve of a resolution that is critical of the Indian Ocean island nation.
Sri Lanka is under international pressure to deal with war crimes allegedly committed in the final stage of a 26-year conflict, in which the army defeated separatist Tamil Tiger rebels five years ago.
The United States has presented a draft resolution at the United Nations Human Rights Council to investigate "past abuses and to examine more recent attacks on journalists, human rights defenders, and religious minorities."
The vote is scheduled to be held on Thursday at the 47-member-state forum in Geneva.
Navi Pillay, U.N. High Commissioner for Human Rights, said that none of Sri Lanka's various domestic mechanisms to investigate past violations had the independence to be effective or inspire confidence among victims and witnesses.
Addressing a session of the rights forum, she said new evidence continues to emerge and witnesses are willing to come forward to testify before international inquiries in which they have confidence and which can guarantee their protection.
"This shows that an international inquiry is not only warranted, but also possible, and can play a positive role in eliciting new information and establishing the truth where domestic inquiry mechanisms have failed," Pillay said.
"We are thus recommending the Council to establish an independent international inquiry mechanism to further investigate the alleged violations of international human rights and humanitarian law, and monitor domestic processes."
Ravinatha Aryasinha, Sri Lanka's ambassador to the U.N. in Geneva, said that the move to set an international probe "reflects the preconceived, politicised and prejudicial agenda which has been relentlessly pursued with regard to Sri Lanka."
Hundreds of protesters marched towards the U.S. embassy in the Sri Lankan capital Colombo, demanding that the resolution be withdrawn.
Abdul Razik, secretary general of Sri Lanka Thawheed Jama'ath, an Islamic religious organisation, said: "We do not want solutions from foreign countries for our problems."
The U.N., through two previous U.S.-sponsored resolutions, has urged Sri Lanka to implement the recommendations of a local panel appointed by President Mahinda Rajapaksa, which also urged punishment for soldiers involved in war crimes.
The third resolution comes after Sri Lanka failed to implement the recommendations, amid continued alleged rights violations. Sri Lanka has stubbornly rejected any international probe.
"Instead of investigating those responsible for atrocities, the Sri Lankan government has cynically absolved its forces of any wrongdoing and lashed out at those seeking accountability," said Human Rights Watch Geneva director Juliette De Rivero.
"Passing this resolution will send a strong message to all victims of Sri Lanka's war that they have not been forgotten," she said in a statement.
The alleged violations have continued despite the end of the war, with reports of intimidation of human rights defenders and journalists, and threats and violence against minority Muslims and Christians.
Pillay, in a report last month, said she had received information on 280 cases of threats and violence against Muslims and 103 against Christians in 2013 alone. (Additional reporting by Stephanie Nebehay in Geneva; Writing by Shihar Aneez; editing by Stephanie Nebehay and Mark Trevelyan)