A huge fire that burned the largest shopping center in the Polish capital Warsaw to the ground a year ago was set deliberately by people acting on behalf of Russia, Donald Tusk said Sunday.

European countries, particularly those in the east of the bloc, have been plagued by Russian espionage in recent years. Arson attacks are another common tool used as part of Russia’s hybrid warfare strategy.

“We now know for sure that the great fire of the Marywilska shopping center in Warsaw was caused by arson ordered by Russian special services,” Tusk said. “Some of the perpetrators have already been detained, all the others are identified and [are being] sought. We will get you all!”

Tusk had said in March that evidence from Lithuania suggested Russia was to blame for the attack, in line with suspicions in Poland, but his statement on Sunday was unequivocal in assigning responsibility to Russia.

The Lithuanian investigation found that a May 9, 2024 arson attack on an IKEA store in Vilnius, as well as the May 12, 2024 Marywilska fire, were set by Ukrainian citizens acting on behalf of Russia, Tusk wrote in March. A week earlier, Polish prosecutors had said a Belarusian refugee was responsible.

Nobody was injured in the fire in Warsaw.