Five people have been arrested on suspicion of planning to attack a Danish newspaper that outraged Muslims in 2005 with cartoons of the Prophet Muhammad.
Denmark's PET security police said the suspects had planned to enter a Copenhagen office block housing several newspapers, including offices of the daily Jyllands-Posten, to 'kill as many as possible of those around'.
Police found a machine gun with a silencer, ammunition and plastic strips that could be used as handcuffs, PET said. It did not say where the items had been seized.
'On the basis of the investigation, it is the PET's assessment that the detainees were preparing a terror attack against a newspaper, which according to the PET's information was Jyllands-Posten,' it said.
'It is likewise the PET's view that the attack was due to be carried out in the coming days.'
Jyllands-Posten was the newspaper that first published the cartoons, provoking protests against Danish and European interests in the Middle East, Africa and Asia in which at least 50 people died.
Danish Justice Minister Lars Barfoed said those detained have a 'militant Islamic background' and called the plan the most serious such attempt in Denmark so far.
Three of the detainees are Swedish citizens, the Swedish security police force SAPO said in a statement. Four were arrested in Denmark and one in Sweden.