Polish authorities detained a Ukrainian citizen on Tuesday for allegedly working with Russian intelligence on a sabotage campaign, the country’s top prosecutor said.

Prosecutors claimed the suspect and others planned to send shipments containing explosives and incendiary materials to Ukraine, intended to spontaneously ignite or explode during transport.

The alleged goal of the operation was to intimidate populations and destabilize EU countries supporting Ukraine.

Two additional Ukrainian citizens suspected of involvement were arrested in Romania, according to Polish officials.

The detainee in Poland was among eight people recently arrested on suspicion of preparing sabotage acts across the country.

Prime Minister Donald Tusk confirmed the arrests on social media, while Special Services Coordinator Tomasz Siemoniak described the suspects’ activities as reconnaissance of military and critical infrastructure, preparing sabotage resources, and carrying out attacks.

Poland has detained dozens over suspected sabotage and espionage since Russia invaded Ukraine in February 2022, ABC News has reported.

Last month, Lithuanian prosecutors uncovered a Russia-linked network planning arson attacks in multiple European countries.

Western officials have documented numerous Russia-linked attacks across Europe since the Ukraine invasion, including car sabotage, cargo plane bomb plots, arson, hacking, and espionage.

The incidents reflect ongoing efforts by Russia and its proxies to disrupt European security and intimidate nations backing Ukraine.