WARSAW, Poland (AP) — Poland has arrested 18 people on allegations of pursuing hostile activities or planning sabotage on behalf of Russia and Belarus, including plans to assassinate Ukraine’s President Volodymyr Zelenskyy, the interior minister said Monday.

Ten of those arrested since December were directly involved in planning various forms of sabotage across Poland, Interior Minister Tomasz Siemoniak told a news conference.

Polish authorities have linked some recent arsons or attempted arsons to Russian-sponsored agents. Polish, Belarusian and Ukrainian nationals are among those arrested in recent months, according to the Internal Security Agency’s communiques.

A Polish man was arrested in April on allegations of being ready to spy for Russia’s military intelligence in an alleged plot to assassinate Zelenskyy, Polish prosecutors have said. The man was allegedly seeking contact with Russians directly involved in the war in Ukraine and was expected to pass on detailed information about the strategic Rzeszow-Jasionka airport in southeastern Poland, near the border with Ukraine.

Siemoniak said that acts of sabotage were apparently part of a wider plan that also includes cyberattacks,pushing migrants in Belarus to cross into Poland, and threatening the security of the country that has been supporting Ukraine in fending off Russia’s full-scale invasion.

“We have no doubt that on the bidding of a foreign country, Russia, there are some people active who are ready to threaten the life, health and property of the Polish citizens,” Siemoniak said.