In the low-level buildings of Campus Risbergska in Orebro, a 35-year-old man stalked the corridors looking for his targets.

Students prayed under their desks and trapped teachers sent desperate texts to loved ones when a gunman opened fire at an adult education centre in Sweden, leaving 11 people dead. Armed police exchanged shots with the suspect at the Risbergska School, an adult campus in the city of Orebro, some 125 miles west of Stockholm.

The gunman’s motive hadn’t been determined by early Wednesday as the Scandinavian nation — where gun violence at schools is very rare — reeled from an attack.