"Denmark's intelligence service on Wednesday arrested four people suspected of planning an 'imminent'' terror attack against a newspaper that printed the controversial Prophet Muhammad cartoons," the Associated Press writes.
The BBC says "a pistol fitted with a silencer was found on the group held in Denmark."
A fifth suspect has been arrested in Sweden.
Jakob Scharf, the head of the Danish Security and Intelligence Service, tells reporters that "an imminent terror attack has been foiled" and more arrests may be coming.
Muslims around the world staged sometimes violent protests after the Jyllands-Posten newspaper published the cartoons in 2005.