The Sept 20 attack was carried out by a suicide bomber in a dumper truck who detonated 600 kilogrammes of explosives outside the luxury hotel, killing at least 60 people and wounding more than 260.

'We obtained a seven-day remand for the four suspects who were produced before the court on Friday,' police official Altaf Khattak told AFP.

The men were arrested recently from Islamabad and the neighbouring garrison city of Rawalpindi, he said.

No further details of their identities or their affiliations were available.

Mr Khattak said the suspects would be interrogated by a joint investigation team comprising senior police and intelligence officials.

Pakistani officials have said they suspect Osama bin Laden's Al-Qaeda network was behind the attack, one of the most devastating in the the country's history.

There has been no claim of responsibility. -- AFP