(AFP) - Prime Minister Dr Mahathir Mohamad today defended the use of a feared security law to detain without trial 10 people and denied it was a crackdown against the opposition.

The 10, including the son of the opposition Parti Islam SeMalaysia's (PAS) spiritual leader, were detained last week under the Internal Security Act (ISA) which allows indefinite detention without trial.

At least five others are also PAS members.

They were detained on suspicion of being members of a "Mujahideen Group" who received military training in Afghanistan and were waging a "holy war" in Malaysia.

Mahathir said the arrests were not politically motivated.

"If it was politics, big (opposition) leaders ... will be arrested but we have not arrested them because they did not create trouble. If there is proof of their trouble-making, we'll also detain them," he was quoted as saying by Bernama news agency.

The arrests came as PAS defied a two-week-old police ban on open-air public rallies and pledged to continue with its political gatherings.

Opposition leaders have voiced concern that the arrests were part of a massive crackdown against dissent.

'Police evidence'

Mahathir said police had evidence that the detainees received military training abroad and had returned to Malaysia to topple the government.

He claimed one of the detainees who is a cake seller had learnt to make and detonate bombs.

"The ISA has to be used against those intending to create chaos and resort to violence in the country. The government has the evidence before taking action," he added.

Police in June detained nine members of a group linked to a spate of crimes including robbery, murdering a politician and bombing a church and Indian temple.

Opposition leaders and rights groups have condemned the use of the ISA, and called for the 10 to be charged in open court.

'Comfortable life'

But Mahathir said preventive laws such as the ISA had brought peace and development to Malaysia.

"If not for these laws, we will not be able to have a comfortable life ... there are many attempts to recolonise us even though not in the military aspect," he said.

He said many developing countries cannot afford to carry out credible development because riots and rebellion mean funds have to be used to maintain security.

"If we were to wait until an offence is committed, not only will the people become victims, the problem may no longer be able to be curbed," he said.

Palestine-Israel example

"Even in Palestine there are preventive laws ... to prevent attacks by Palestinians, Israel does not arrest the Palestinians but instead launch rocket attacks on people suspected of planning to attack them even before these people commit any crimes or attacks."

In Malaysia, he said detainees under preventive laws were allowed to meet family members and given sufficient food.

"But Israel kills people they suspect to be planning to launch attacks against them and this is sanctioned by the most powerful government in the world," he added, in an apparent reference to the United States.