Sri Lankan authorities will appoint a commission to investigate a mass grave where more than 150 skulls and bones were found last year, a government spokesman says.
Lakshman Hulugalle, head of the government's Media Centre for National Security, said on Monday President Mahinda Rajapaksa had taken the decision.
The grave, with skulls and bones of people thought to be Marxist rebels killed decades ago, is located at a state-run hospital in the central region of the country, said Hulugalle.
He told reporters the commission's probe would be carried out alongside an ongoing police investigation.
Names of the members of the commission will be announced soon, he added.
Workers found the remains while doing construction last December at the hospital in Matale, about 105km, northeast of the capital, Colombo.
The skeletons were found buried in neat rows, five or six stacked on top of one another, totalling 154 bodies.
Last month, a judge declared the mass grave a crime scene, saying the skulls and bones recovered dated back 25 years and strengthened suspicions that they belonged to suspected Marxist rebels killed at the time.
Magistrate Chathurika de Silva told a court in Matale that tests carried out by archeological and judicial medical officials showed the remains dated to between 1987 and 1990.
During that period, thousands of men and women suspected of having ties to the rebels disappeared after being arrested by security forces.
When the bodies were found, there were initial claims that they belonged to those killed in an epidemic in the 1940s or in a mudslide.
But hospital authorities did not have any records of bodies buried on the premises.
A Marxist group, the People's Liberation Front, which led two uprisings first in 1971 and again in 1987 to 1989 against the government, said the bodies may belong to its members killed by security forces and demanded that the government to conduct a full investigation.
The Marxists were mostly rural Sinhalese, the country's majority ethnic community. They complained of economic disparities and said that rural people were denied equal opportunities.