Head of Denmark's PET security police Jakob Scharf talks to the media at a news conference in Copenhagen December 29, 2010. [Photo/Agencies]

In Sweden, police said they arrested a 37-year-old Swedish citizen of Tunisian origin living in Stockholm.

"I am shocked that a group of people have concrete plans to commit a serious terrorist attack in this country," Danish Prime Minister Loekke Rasmussen told reporters. "I want to stress that regardless of today's event it remains my conviction that terrorism must not lead us to change our open society and our values, especially democracy and free speech."

The alleged plot follows several attacks and threats connected to 12 cartoons depicting the Prophet Muhammad published by the Jyllands-Posten in 2005 as a challenge to perceived self-censorship. The cartoons also provoked massive and violent protests in early 2006 in Muslim countries after the drawings were reprinted in a range of Western media. Islamic law generally opposes any depiction of the prophet, even favorable, for fear it could lead to idolatry.

Zubair Butt Hussain, a spokesman for the Muslim Council of Denmark, called the alleged plot "extremely worrying."

The organization "absolutely condemns any act of terrorism regardless of the motives and motivations that may lie behind," Hussain said.

Kurt Westergaard, the artist who drew the most contentious of 12 cartoons, said the foiled plot was "a direct attack on democracy and freedom of press."

"We may not and won't let anyone forbid us to criticize radical Islamism. We may not be intimidated when it comes to our values," Westergaard told the German tabloid Bild.