Lars Vilks' has been living under an Islamist death threat
Seven people have been remanded in custody for a further 72 hours in the Irish Republic over an alleged plot to murder a Swedish cartoonist.
The suspects were arrested by Irish police on Tuesday.
They are accused of hatching a plot to kill Lars Vilks over a cartoon he drew depicting the Prophet Muhammad with the body of a dog.
Meanwhile US authorities announced they have charged a Philadelphia woman with plotting to kill Mr Vilks.
The woman, Colleen LaRose - who described herself online as "Jihad Jane" - was arrested in Philadelphia in October 2009.
Unconfirmed reports say she travelled to Ireland in September and met several of the suspects who have been arrested there.
She had arrived in Ireland from the Netherlands, where she began a trip to Europe to inquire how to obtain residency in Sweden, according to a report in the Irish Independent.
The suspects being held in Ireland were arrested in Waterford and Cork as part of an international investigation into alleged death threats against Mr Vilks.
They include four men and three women and it is understood that they are Muslims - three Algerians, one American, one Libyan, one Palestinian and one Croat.
Two - understood to be a Croatian man and an American woman - had their detention extended by Waterford District Court on Thursday, while the other five had theirs extended at a special court sitting late on Wednesday.
The Vilks controversy arose in 2007, when his entry in an arts project was published by the Swedish newspaper Nerikes Allehanda.
It pictured a dog with the head of a bearded man in a turban. Several Muslim countries protested against the picture.
In 2007 a group linked to al-Qaeda in Iraq offered a $100,000 reward for killing Mr Vilks, and a 50% bonus if he was "slaughtered like a lamb" by having his throat cut.
Several Muslim countries also protested against the picture.
At the time, Swedish officials expressed regret at any hurt caused to Muslims' feelings, but said the government could not prevent the publication of such drawings because of media freedom rules.
The case came about a year and a half after a series of depictions of Muhammad in Denmark's Jyllands-Posten paper caused protests by Muslims around the world in early 2006.
Mr Vilks, who was temporarily moved to a secret location, told the Associated Press this week that he had built himself his own defence system, including a "safe room" and a barbed-wire sculpture that could electrocute potential intruders.
"If something happens, I know exactly what to do," he said.
Mr Vilks says he has recent a number of recent death threats by telephone.
Several newspapers in Sweden reprinted Mr Vilks' controversial cartoon on Wednesday.