Police in the Polish town of Sierpc detained a 17-year-old student after he allegedly told classmates that he intended to do “something bad at school.” The students informed a teacher, who promptly contacted the local district police.

inPoland.net.pl reported the case on Thursday, October 8. Authorities said the swift response by the pupils, school staff and officers may have prevented a possible attack.

Two officers went to the teenager’s residence on the morning of August 7 and arrested him. They found two knives in his bag, while searches stored on his phone reportedly contained material connected to the suspected plan. The device was confiscated for examination.

The teenager remains in a holding cell at the Sierpc police station. Investigators are carrying out further procedures and interviewing witnesses.