WARSAW, Poland, June 12, (AP): Polish security services have detained a 19-year-old man suspected of planning a terrorist attack, marking the third arrest in an ongoing investigation in the northeastern city of Olsztyn, a government official said Thursday. The Internal Security Agency said the suspect, along with two others previously arrested, had gathered extensive materials related to firearms use, combat tactics, and explosive devices.

Prosecutors allege the group trained at shooting ranges and conducted paramilitary-style drills. Investigators believe the suspects were influenced by mass killers, including Anders Breivik, Brenton Tarrant, and Timothy McVeigh.

The young men reportedly studied those attacks in detail, analyzing the assailants’ methods and mistakes, according to the statement. "They were fascinated by their ideology, studied how the attacks were carried out, and analyzed the mistakes that were made. The content they consumed contributed to the development of extremely radical moral attitudes,” the security agency said.