Polish and Romanian authorities have detained eight people suspected of planning acts of sabotage for Russia, including a new plot involving explosive parcels intended for Ukraine, officials in Warsaw said on Tuesday.

Three of the arrests were linked to the alleged parcel plot, which Polish investigators believe was designed to send explosives through Poland and Romania into Ukraine.

“Preliminary information indicates that they created a route of some kind to send explosives through Poland and Romania to Ukraine,” said Jacek Dobrzynski, spokesperson for Poland’s Special Services Coordinator.

He confirmed that a 21-year-old Ukrainian suspect was arrested near Warsaw, while his accomplices were detained by Romanian intelligence officers in Bucharest.

According to Poland’s National Prosecutor’s Office, the shipments were meant to combust or explode in transit, aiming to intimidate civilians and destabilize European Union member states supporting Ukraine.

Romania’s anti-organized crime agency, DIICOT, said that on October 15, two Ukrainian nationals left packages containing homemade explosive devices at an international delivery firm in Bucharest, intending to destroy the building by fire.

“The devices were dismantled by specialists. They are currently detained for 30 days,” DIICOT said in a statement.

Romania’s intelligence service, SRI, added that the two suspects acted under “direct coordination of representatives of Russian secret services,” targeting an office of the Ukrainian courier company Nova Post in Bucharest.

Polish officials say the plot is part of a broader “hybrid war” waged by Russia, using tactics like arson, sabotage, and cyberattacks to undermine European nations backing Kyiv. Moscow has repeatedly denied such accusations.

Dobrzynski said Poland’s Internal Security Agency has detained a total of 55 people in recent months for allegedly acting on behalf of Russian intelligence.

European officials have previously accused Russia of orchestrating parcel explosions across Europe in 2024, calling them test runs for a potential plan to trigger detonations on cargo flights to the United States — claims Moscow has also denied.