But the group behind it?

Bomb threats: Only four emails from Swiss nationals

In the fall, a bomb threat was received against Graz Central Station, among others.(Bild: Christian Jauschowetz)

The bomb threats last fall are probably not just the work of one individual. According to the latest investigations, an "unknown group of perpetrators operating from Germany" is suspected. There is now also an indication of a possible motive.

The threats were probably intended to "scare the authorities", said Ulrike Breitender from the Linz public prosecutor's office. It was "a special case of cyberbullying". The suspects have not yet been identified.

As reported, it was initially assumed that only a Swiss man was involved, who was 20 years old at the time of the attack. Four threatening emails have been attributed to him so far. However, he is still at large and has access to his laptop and cell phone. The argument against arrest is the lack of documents.

The bomb threats against several Austrian train stations, schools and shopping centers were mainly sent by e-mail to their provincial police directorates at the end of September and beginning of October. 690 trains were affected. They were either unable to run at all, ran late or had to skip individual stops.