Polish security forces detained eight suspects accused of working with Russian and Belarusian intelligence to plan sabotage operations.
Intelligence chief Tomasz Siemoniak said they scouted military sites, prepared explosives, and carried out attacks.
One suspect reportedly operated across Poland and Romania, with two accomplices arrested in Romania.
Authorities say the arrests are part of a wider crackdown, with 55 people detained in recent months over similar espionage and sabotage activities targeting Polish and NATO infrastructure.
