German police have arrested an 18-year-old man on suspicion of planning violence endangering the state after he threatened to kill people in online posts and posted right-wing extremist and anti-Semitic content, Reuters reports.

Police in the western state of Hesse searched the apartment of the suspect last Wednesday and seized computers, arms and ammunition, the State Office of Criminal Investigation and the public prosecutor’s office in Frankfurt said in a statement.

The suspect had repeatedly published posts online in which he threatened to kill people for political reasons, it said. Several months of investigation had revealed the suspect’s “consolidated violent, anti-Semitic and right-wing extremist attitude” according to the Hesse state authorities.