Polish prosecutors announced Monday that they had launched a terrorism investigation into a fire at a drone factory.
The fire at the WB Electronics factory in the central city of Skarzysko-Kamienna was started deliberately, a prosecution statement said.
Authorities have not said who was suspected, but Poland, a key ally of neighbouring Ukraine, has accused Russia several times of attempted sabotage since its 2022 invasion of Ukraine.
Firefighters took two hours to control the fire early Monday and the country's ABW intelligence agency has joined the investigation with the police.
The prosecution statement said an investigation had started "for participation in the activities of a foreign intelligence service directed against the Republic of Poland and for a terrorist offence, consisting of deliberately causing a fire on the premises of the WB Electronics factory using a device containing flammable materials."
Several countries in eastern Europe have said they have been the target of spying and sabotage as part of a "hybrid war" they blame on Russia.