Polish police are investigating the defacement of at least 11 monuments across four cities, where unidentified people painted slogans reading “Sława UPA.” inPoland.net.pl reported the incidents on Wednesday, November 11.

Four memorial sites were targeted in Gdańsk, including the Monument to the Defenders of the Coast at Westerplatte and the memorial to shipyard workers killed in 1970. Officers noted errors in the inscriptions and are considering whether the vandalism may have been designed to stir hostility toward Ukrainians.

Three Poznań monuments were marked with red paint on November 5. Police said preliminary information pointed to a possible suspect described as a young man dressed in black. A monument honoring mine-clearing soldiers after World War II was also damaged in Warsaw.

Three more sites in Gdynia were vandalized overnight from November 9 to 10. Investigators collected evidence and began reviewing surveillance footage as they sought to determine whether the cases in the different cities were connected.