STOCKHOLM (AP) — Five men have been arrested “on suspicion of aiding and abetting terrorist offenses,” Sweden’s SAPO domestic security agency said Tuesday, adding the case was related to the burning of a Quran in January in Stockholm and that an attack is not imminent.

In a statement, Susanna Trehörning, deputy head of SAPO’ s counterterror unit said that the case had “international links to violent Islamist extremism.” Swedish public radio said the suspects had links to the Islamic State group.

Trehörning said that Tuesday’s arrests came following “extensive intelligence and investigative work “after the protests that were directed at Sweden in connection with the high-profile burning of the Quran in January and where there are international calls for attacks.”

She told Swedish broadcaster SVT that the suspects were in ”a planning phase” and that they “had not immediately thought of doing anything here and now.”

In January, a far-right activist from Denmark received permission from police to stage a protest outside the Turkish Embassy in Stockholm where he burned the Islamic holy book.

That angered millions of Muslims around the world and triggered protests. NATO-member Turkey said it wouldn’t allow Sweden to join the military alliance as long as the Scandinavian country permits such protests to take place. In Sweden, such demonstrations are protected by freedom of speech.

All NATO members need to ratify in their parliaments the accession requests by Sweden.

Finland which sought NATO membership at the same time as Sweden is expected to join the alliance later Tuesday after all 30 member states ratified the Finns’ accession request, but Turkey is holding out on ratifying Sweden’s membership.

In February, Swedish police denied permission for protests involving the burning of a Quran, fearing they could provoke terror attacks or attacks against Swedish interests.

On Tuesday, Sweden’s Administrative Court ruled that freedom of assembly and demonstration are constitutionally protected rights and overturned the police decision, saying security risk concerns were not enough to limit the right to demonstrate.