The threat message was first sent by e-mail, but also popped up on social media. Police considered the case serious enough to start an investigation. They visited the university campus "Drie Eiken" in Wilrijk, first to inform everyone.
Safety measures were introduced later on, when nobody was allowed on the site and the people in the building had to stay inside. Everyone was allowed home around 4.30 p.m.
An 18-year-old suspect was arrested in his car on Linkeroever and taken in for questioning late yesterday, after it turned out he owned the account from which the threat message was sent. The youngster was being questioned for quite a while, but there was not enough evidence that he sent the message. He was released later on. The judicial authorities say there are no indications that the threat is still concrete at present.