Three suspects appeared in a Danish court Thursday in relation to a foiled "Mumbai-style" plot to massacre staff at a newspaper that published caricatures of the Prophet Mohammed, a spokeswoman for Danish intelligence said.

"Three of the suspects are appearing in court right now," Trine Marie Ilsoee, a spokeswoman for Danish intelligence agency PET, told AFP Thursday.

"The three suspects that came from Sweden are appearing in court" in the Copenhagen suburb of Glostrup, she said.

Danish and Swedish intelligence agencies said Wednesday they had arrested five men who were planning an imminent assault on the Copenhagen offices of the Jyllands-Posten daily.

According to PET, they were planning to "kill as many people as possible" and police seized a sub-machine gun in connection with the arrests.

Four men -- including three who had travelled to Copenhagen overnight to Wednesday from a Stockholm suburb -- were arrested in Denmark, and one was arrested in the greater Stockholm area.

Danish media reported that the fourth man arrested in Denmark, a 26-year-old Iraqui asylum seeker, would be released later Thursday.

The online edition of daily Politiken reported the man would be later charged with "trying to conduct terror."

Swedish media reported the man arrested in Stockholm, 37-year-old Swedish citizen, was due to appear in court in the Attunda court in Stockholm suburb of Sollentuna Thursday.

Jyllands-Posten published a dozen cartoons in 2005 insltuting  Prophet Mohammed, which triggered angry and sometimes deadly protests around the world.