COLOMBO, Sri Lanka - An international rights group welcomed Sri Lanka's decision to free all war refugees from camps, but said Wednesday that thousands of other Tamils remain unlawfully detained.

The government said last week it would release the remaining 136,000 ethnic Tamil refugees held in squalid and overrun government camps on Dec. 1.

Some 300,000 war refugees were forced into the camps in the final months of the government's decades-long civil war with Tamil Tiger rebels, which ended in May.

New-York based Human Rights Watch group called the government's decision "a positive step," but expressed concern for the more than 11,000 people being held without charge on suspicion of rebel involvement.

The government is failing to provide those detainees with their basic rights under Sri Lankan and international law, the group said, urging the government "to either bring charges against these security detainees or release them."

There was no immediate comment from the government, which has said the detained former rebel fighters are being rehabilitated in state-run centres.

Government troops routed the Tamil Tigers in May, ending their 25-year fight for an independent homeland for the country's minority Tamils. An estimated 80,000 to 100,000 people were killed in the violence.