More than two months later, Theventhran, 56, a Tamil civil servant, finds himself once again a captive, this time of the people who freed him from the Tigers’ grip. “We were liberated,” he said in an interview at one of the sprawling, closed camps set up to house those displaced in the war against the Liberation Tigers of Tamil Eelam. “Now we are prisoners again. I lost everything in this war. The Tigers killed my son. I lost my property. Now I have lost my freedom, too.”

Thousands of Tamils remain locked in camps almost entirely off limits to journalists, human rights investigators and political leaders. The government says the people in the camps are a security risk because Tamil Tiger fighters are hiding among them. But diplomats, aid workers and many Lankans worry that the historic chance to finally bring to a close one of the world’s most enduring ethnic conflicts is slipping away, as the government curtails the rights of Tamil civilians in its efforts to stamp out the last remnants of the Tigers.

“The government told these people it would look after them,” said Veerasingham Anandasangaree, a Tamil politician who has been a staunch supporter of the government’s fight against the Tamil Tigers. “But instead they have locked them up like animals with no date certain of when they will be released.”

The government has portrayed its final battle against the 26-year insurgency by the Tamil Tigers, which ended in late May with the killing of the group’s leader, Velupillai Prabhakaran, as a rescue mission to liberate civilians held hostage by one of the world’s richest and most ruthless armed groups.

“We can’t say this was a war; it was a humanitarian operation to safeguard the people of the area,” said President Mahinda Rajapaksa last week. “They knew we were not against the Tamil people, against the civilians. This was only against the terrorists.”

Although many of the camps’ residents are grateful to the government for freeing them from the rebels, frustration and anger are building as it becomes clear that reconciliation and finding a political solution to the grievances of the Tamils and other minority groups will have to wait. Camp conditions have improved since the early days in April and May when the sudden influx of hundreds of thousands of people caught the government and aid groups flatfooted.

Hundreds of shelters are being built to replace flimsy tents. Children are attending schools, and health centers are helping check the spread of diseases. But that has done little to tamp down the impatience of those living here.