The U.N. Human Rights Council on Thursday launched an inquiry into alleged war crimes in Sri Lanka, a move angrily rejected by Colombo as counter-productive.

In a 23-12 vote, the council backed a Western-sponsored resolution saying it was time for a "comprehensive investigation into alleged serious violations and abuses of human rights and related crimes by both parties in Sri Lanka".

Sri Lanka's military admitted on Saturday soldiers had abused and tortured female recruits, a rare admission of guilt after years of allegations over its personnel's treatment of Tamil rebels during an uprising.

A military spokesman said it accepted the authenticity of a video leaked on a dissident website that appeared to show soldiers torturing women soldiers, adding instructors had overstepped their authority for an undisclosed act of violating "military discipline".

The "highest levels" of Sri Lanka's government were complicit in raping, torturing and abducting ethnic Tamils following the nation's ethnic civil war, a report by rights groups warned Friday.

Authorities carried out horrific sexual abuse on Tamils, including forced oral sex and anal rape as well as water torture, the report by the UK Bar Human Rights Committee and International Truth & Justice Project found.

Sri Lanka has released two leading rights activists after their detention under strict anti-terrorism laws triggered international condemnation, police and supporters said on Wednesday.

Father Praveen Mahesan, a Catholic priest who heads the Peace and Reconciliation Center in the war-torn Jaffna region, and Ruki Fernando of the Colombo-based INFORM advocacy group were detained on Sunday as they met relatives who lost loved ones during the Tamil separatist conflict.

Sri Lankan authorities halted excavations after recovering 81 skeletal remains from an unmarked mass grave atop an old burial ground in the island's former war zone, an official said Saturday.

Judicial medical officer Dhananjaya Waidyaratne said digging at a depth of about two meters (6.7 feet) led to the old cemetery and the authorities did not want to go deeper and disturbed those who had been properly buried.

Sri Lanka on Wednesday dismissed a U.N. report calling for an international probe into allegations of war crimes at the end of its civil war as "fundamentally flawed."

Foreign Minister Gamini Lakshman Peiris said his government rejected a report from U.N. human rights chief Navi Pillay "in its entirety," describing it as "arbitrary, intrusive" and "fundamentally flawed."

A U.S.-led resolution calling for an international probe into allegations that 40,000 civilians were killed at the end of Sri Lanka's separatist war has been filed with the U.N.'s top rights body.

In a draft resolution posted on the Human Rights Council's website on Tuesday, the United States endorses U.N. human rights chief Navi Pillay's call for an external investigation into alleged war crimes in the final stages of Sri Lanka's Tamil civil war in May 2009.

Another unmarked mass grave has been found in Sri Lanka's former war zone, police said Saturday, as Colombo braced for a U.S.-led censure resolution at the U.N. rights forum next week.

A family on Friday stumbled upon nine bodies buried in the garden of their home in the district of Mullaitivu, where the final battles of the island's protracted ethnic war were fought in May 2009, police spokesman Ajith Rohana said.

Sri Lanka's president on Friday acknowledged his discomfort at the prospect of being censured by the U.N.'s top rights body, as he accused Washington of treating Colombo like Muhammad Ali's "punching bag".

The United States is the author of a resolution due to be voted on by the United Nations' Human Rights Council in Geneva on March 28, which accuses Sri Lanka of failing to investigate allegations of war crimes at the end of its conflict against Tamil separatists in 2009.

Sri Lanka has instilled a "climate of fear" as it intensifies its repression of critics in the build-up to Colombo's expected censure by the U.N.'s Human Rights Council, Amnesty International said Wednesday.

In a new report, the London-based advocacy group documented the cases of several human rights defenders who had been targeted for harassment and surveillance by the Sri Lankan regime, including death threats.