The man lives in the Stockholm area and is suspected of being involved in violent right-wing extremist circles.
The suspicions concern violent right-wing extremism, and he was arrested during a planned operation on Wednesday, says Jonathan Svensson, press spokesman at Säpo.
The man is in his 20s. The alleged crimes were committed in Stockholm County and elsewhere in the country from November last year until his arrest on Wednesday, which Expressen first reported.
According to the criminal record, the man has no previous convictions.
Detention hearings are being held this morning.
