Prime Minister Abdullah Ahmad Badawi defended the detention without trial of 13 Malaysian students under a tough security law, saying the government has to investigate their links to the Jemaah Islamiah (JI) terror group.

The 13 were arrested by police under the Internal Security Act (ISA), which allows indefinite detention without trial, when they arrived Monday from Pakistan in a special aircraft.

The students, who were studying at two institutions in Karachi, were held by Pakistan authorities in September on suspicion of terrorist activities or links to terrorists.

"Understanding that they may be JI cadres who are to be given training in Pakistan and to continue with the activities of the JI today, it is important security-wise to investigate the extent of their involvement," Abdullah was quoted as saying by Bernama news agency.

Abdullah, who is also home minister, gave an assurance that the students would be released if investigations showed that they were not involved.

"If there's nothing, there's no reason for us to hold them under the ISA," he said.

Same old policies

The opposition party PAS criticised the arrests under the ISA, saying it was cruel and urged the government to free the students or charge them in court if it has evidence of their alleged terrorist activities.

"If the government is against terrorism, then it should charge the detainees in court because detention without trial is a form of terror act," PAS youth wing said in a statement.

It said the ISA detentions, which came just 10 days after Abdullah succeeded Dr Mahathir Mohamad, who retired Oct 30 after 22 years in power, was a signal that the "cruel and iron rule policies adopted by Mahathir will be continued by the new administration".

Deputy Home Minister Chor Chee Heung last month said the 13 students were being trained as future leaders of the al-Qaeda-linked JI network, accused of responsibility for a string of terror attacks including the Bali bombing in Indonesia last October which killed 202 people.

He said investigations revealed some of the students were children of alleged JI members already in detention in Malaysia, and had received preliminary training at an Islamic school in the country run in the past by senior JI figures.

Malaysia has detained 94 suspected Islamic militants over the past two years, with 69 of them allegedly JI members, police said. - AFP