A Ukrainian citizen has been arrested in Poland, allegedly in connection with a sabotage campaign carried out on behalf of Russian intelligence agencies, while two others were arrested in Romania, reports Associated Press.

Prosecutors stated that the individuals acting on behalf of Russian intelligence allegedly prepared sabotage operations related to cargo shipments in Ukraine. These included explosives and incendiary materials designed to ignite or detonate during transportation.

Polish prosecutors said the aim was to intimidate the public and destabilize EU countries supporting Ukraine, adding that two more Ukrainians were arrested in Romania on suspicion of participating in the same plot.

Romanian authorities reported on Tuesday that two Ukrainians, aged 21 and 24, acting on behalf of Russian intelligence, delivered two parcels containing improvised explosive devices to an international delivery company in Bucharest.

Romanian intelligence specialists defused the devices, and the detainees have been placed under preventive detention for 30 days.

In Poland, the arrested Ukrainian was one of eight individuals recently detained by authorities on suspicion of preparing sabotage operations in the country, according to a spokesperson for the National Prosecutor’s Office. Polish Prime Minister Donald Tusk posted about the arrests of the eight individuals on the X social media platform.

Tomasz Semoniak, the minister coordinating Polish intelligence services, stated that the operations mentioned by Tusk involved “reconnaissance of military facilities and critical infrastructure, preparation of resources for sabotage, and the execution of direct attacks.”

Since the start of the war in Ukraine, Polish authorities have arrested dozens of people on suspicion of sabotage and espionage.