The new suspect in a threat to shoot a teacher and pupils at an unnamed school in Leiden is an 18-year-old youth travelling around Latin and South America, the public prosecution department says.

The youth went to school in Leiden and ‘had an interest in weapons’. He also gave a school presentation about school shootings in the US, the department said. According to his family, he plans to spend some time in Costa Rica.

Officials are now trying to locate where the boy is staying in the hope of bringing him back to the Netherlands to face charges. The public prosecutor does not rule out issuing an international arrest warrant for the youth.

The threat, made on internet site 4chan, led to all secondary schools in Leiden being shut on Monday and put under armed guard. Another boy was arrested in connection with the case but released on Tuesday without charge.