Already in September, Säpo got two of the now four terror detainees on its radar and started an investigation.
After a secret and longer operation, the case grew, Säpo struck.
The people have had different roles, but all have a connection to an Islamic cultural association in Tyresö. The investigation also shows that the terrorist crime has international links to IS, mainly IS in Somalia, but also to people under terrorist-related investigation abroad.
– There is a clear connection to domestic organized crime, including through the supply of weapons, says senior prosecutor Lars Hedvall, who is the head of the preliminary investigation.