STOCKHOLM (AP) — Swedish prosecutors say a person has been arrested in southern Sweden on suspicion of preparing a terror offence.

Prosecutor Ewamari Haggkvist says the person was arrested Tuesday, adding the suspicion “is reasonable.”

She said Wednesday she could not give further details but “the reason for the person being arrested is that the suspect could damage the investigation.”

The Aftonbladet tabloid said the man was in his late 30s and his crime was committed after Aug. 21.

Haggkvist said a Swedish court would have to decide before Friday whether to hold the person in pre-trial detention.