"The government has detained people in these camps and is threatening their health and even their lives by keeping them there during the rainy season floods," said Brad Adams, Asia director at Human Rights Watch. "This is illegal, dangerous, and inhumane."

In violation of international law, the government has since March 2008 confined virtually all civilians displaced by the fighting between government forces and the separatist Liberation Tigers of Tamil Eelam (LTTE) in detention camps, euphemistically called "welfare centers" by the government. Only a few thousand camp residents have been released and allowed to return home or to stay elsewhere.

During the last several days, heavy rain fell on northern Sri Lanka, flooding several camps. Zones 2 and 4 of Manik farm, a large complex of camps west of the town of Vavuniya, were particularly affected by rain. More rain is expected with the onset of the rainy season next month, further worsening conditions in the overcrowded camps.

"Aanathi," a 30-year-old woman living in zone 2 with her 1-year-old son, told Human Rights Watch: "Within seconds, the water was pouring into our tents. ... After a couple of minutes, everything was flooded. We lost all of our things. We had no place to cook. We couldn't get help from anybody, because everybody was in the same situation. It was terrible. We were already frightened, and this made it worse."

Seven people from three families were living in Aanathi's tent, which was designed to house five people. According to the United Nations, the majority of the camps are severely overcrowded; zones 2 and 4, with a joint capacity of 50,000 people, held more than 100,000 people as of July 28, 2009. For their protection, the residents who spoke with Human Rights Watch were not identified by their real names.

The rain caused emergency latrines to flood or collapse, causing sewage to flood several areas of the camps, heightening the risk of outbreaks of contagious diseases. "Shantadevi," also in zone 2, told Human Rights Watch: "Some of the toilets are completely flooded. It looks like they are floating in water. The pits have collapsed and raw sewage is floating around with the storm water in a green and brown sludge. It smells disgusting."

Aanathi explained to Human Rights Watch that the area where the camp is located usually floods during the rainy season: "If they don't release us before then, we will be washed away by all the water, there will be outbreaks of diseases here. It will be terrible."

The camps have already suffered from outbreaks of contagious diseases with health officials recording thousands of cases of diarrhea, hepatitis, dysentery, and chickenpox.

Observers report that camp residents are getting increasingly frustrated by the difficult conditions in the camps and that the current heavy rain caused unrest that was quickly defused by the military camp administration without the use of force. In late June, camp residents held at least two protests, which were dispersed by the security forces. Since then, the military administration of the camps, apparently fearing more unrest, has divided the camps into smaller sections, which are easier to control.

Humanitarian organizations have long advocated the release of the displaced from the camps. Many of the camp residents have relatives, including close family members, with whom they can live if they are allowed to leave. Aanathi told Human Rights Watch that she would go to live with her mother in Jaffna or her mother-in-law in Trincomalee if released.

"The camp is like a desert, there are no trees here," she told Human Rights Watch. "When it is sunny, it gets really hot. When it rains, you can't walk because of all the mud. With a 1-year old it is very difficult to move around, and I can't leave him alone in the tent. It is painful to speak about my situation here. I am lonely, very lonely. If I could go to Jaffna or Trincomalee, I would have a good life again."

The government has refused to release the displaced from the camps, contending that it needs to screen them for Tamil Tiger combatants. In response to calls to release them, Foreign Secretary Palitha Kohona, recently named Sri Lanka's ambassador to the UN, told the BBC on August 10 that it was "mischievous to talk of rights in the absence of security."

On August 15, the minister of resettlement and disaster management, Rizad Bathiudeen, told the Sri Lankan Daily Mirror that he held UN agencies responsible for the flooding in the camps, saying, "[T]he Government cannot be blamed for the poor condition of the drainage systems which burst and failed."

"The government bears full responsibility for the situation in the camps," said Adams. "Locking families up in squalid conditions and then blaming aid agencies for their plight is downright shameful."