Terrorism charges against Krekar were dropped last year

Mullah Krekar, the head of Kurdish group Ansar al-Islam, was arrested on Friday at his home in Oslo.

The court ruled there was insufficient evidence against him but ordered him to remain in jail pending an appeal by prosecutors later this week.

US officials suspect that Ansar al-Islam has ties to al-Qaeda.

Mullah Krekar was detained last year on terrorism charges.

But prosecutors say they have now found new evidence against him, relating to a plot to murder rivals in Iraq during 2000-2001.

Police asked an Oslo court to order that Mr Krekar be detained for four weeks while they prepared a case against him.

Following the refusal of the request, prosecutors said they would appeal against the court's decision.

Mullah Krekar has repeatedly denied links with al-Qaeda, although he has called Osama Bin Laden "a good Muslim".

US aircraft targeted Ansar's camps in northern Iraq during the war and US officials have linked the group to the insurgency against coalition forces occupying Iraq.

Norway is seeking to expel Mullah Krekar, who was deported from the Netherlands in January 2003.