Two students have been arrested in connection with a fake bomb warning at Leiden’s hbo college at the end of April.

The two women are aged 19 and 20 and made the bomb warning by telephone. It led to some 300 people being evacuated from the building and widespread disruption of exams.

Police traced the bomb threat to a phone box in The Hague. The women had been captured on security camera and were arrested on Wednesday. They were released later that day.

The bomb warning came a couple of days after an 18-year-old youth had threatened to carry out a mass shooting at a Leiden school which led to all secondary schools in the town being closed for a day.

According to news agency ANP, the police hope to make the women pay for the cost of the evacuation.