The UN high commissioner for human rights urged the Sri Lankan government Tuesday to come clear about the fate of a large group of people who have been missing since the civil war that ended in 2009.
Sri Lankan Prime Minister Ranil Wickremesinghe said most of those people reported missing were probably dead.
Many ethnic Tamil civilians have not been heard of after their arrest during the civil war.
Tamil politicians have prepared a list of more than 4,000 people who are missing.
The list, which included the dates and locations where the missing people were last seen, has been handed over to UN High Commissioner for Human Rights Zeid Ra'ad Zeid al-Hussein, who is on a visit to the country.
Zeid said Wickremesinghe's comment, claiming the missing people were probably dead, had disappointed many families still waiting for their loved ones.
"The statement must be followed by rapid action to identify precisely who is still alive and who has died or been killed, properly account for their deaths — including whether or not they were lawful — identify the location of their remains, and provide redress," Zeid said.
During Zeid's four-day visit to Sri Lanka, he reviewed the country's promised efforts to investigate allegations of wartime abuses by government soldiers and ethnic Tamil rebels, as well as works for the relief of war victims.
Last year, Sri Lanka had pledged to let a foreign-aided investigation go on into allegations of abuse.
Zeid said despite some positive developments there has been a loss of confidence in the government's reform pledges in the Tamil-majority north and east of the country.
The UN official said downsizing the military and freeing private land confiscated by the military would help rebuild confidence.