A Malaysian rights group on Tuesday urged the government to free all detainees held under its strict internal security law, which has been used mainly against what it says are suspected militants.

The call came after the Abolish ISA Movement (GMI) group said it had confirmed that authorities freed four people from detention earlier this month after they spent five years in the northern Kamunting prison camp.

No official reason was given but GMI said the four were being closely watched and were not allowed to stray from their villages.

The four were picked up when Malaysia launched a crackdown on suspected Jemaah Islamiyah (JI) militants in 2002, but GMI said no charges were filed against them.

"We welcome their release, but there was never proof of their involvement in JI activities in the first place," GMI spokeswoman Nalini David said.

"It is very simple. If they were really involved in JI, then just bring out the evidence and charge them instead of just keeping them in detention," she said.

She said none of the "scores of detainees" in Kamunting had been charged or tried in court.

The group slammed what it termed as the "selective release" of detainees.

"GMI urges the detainees to be released, especially after the IGP (Inspector General Police) has confirmed that there is no JI movement here in Malaysia," she said.

Malaysian authorities, invoking the country's Internal Security Act (ISA), rounded up hundreds of people from 2001 to 2003 on suspicion of being members of the JI or its Malaysian affiliate, the Kumpulan Militan Malaysia.

Opposition groups and activists in Malaysia have called for the repeal of the ISA, which they say is abused to silence dissent. The law allows Malaysia to detain people for consecutive two-year terms without trial.