One of the men is the brother of JI suspect Hambali

The six were studying in Karachi when police arrested them more than two months ago.

Officials said they had not been charged with any crime in Pakistan, but that the Indonesian authorities wanted to question them.

They were among 19 students who were captured by Pakistani security officials during different raids on Islamic schools in September.

The other 13 were extradited to Malaysia last month.

Malaysian police said on Wednesday that five of those students had been ordered to be detained in prison for two years. The other eight have been released, although four have had their movements limited.

The authorities accuse Hambali's brother, Rusman Gunawan, of running JI operations in Pakistan.

JI is suspected of carrying out a string of bombings in the region, including that which targeted Bali in October 2002.

Hambali was arrested in Thailand in August and is currently in US custody at an undisclosed location.

There are hundreds of foreign students studying in Karachi's Islamic seminaries.

The government has cracked down on them and many foreign students have been forced to leave because they did not have permission from their governments to study in Pakistan.