Poland will close the Russian consulate in Krakow after finding “proof” that Moscow was behind an “act of arson” last year.

Poland’s foreign minister Radosław Sikorski said he took the decision at around 9 a.m. European time Monday following an evaluation of the fire in a shopping mall in Warsaw.

The huge fire burned the largest mall in the Polish capital to the ground a year ago. Polish Prime Minister Donald Tusk revealed the findings of the assessment on Sunday, saying it was “caused by arson ordered by Russian special services.” He added: “Some of the perpetrators have already been detained, all the others are identified and [are being] sought. We will get you all!”

Sikorski, speaking as he arrived to a meeting of the Weimar-Plus group of ministers in London to discuss the Russia-Ukraine war, said: “An hour ago, I took the decision to close down the Russian consulate in Krakow.

“This is because our justice ministry and security services have found proof that they were behind an act of arson in Poland a year ago.

“This was a huge fire of a shopping mall in Warsaw in which, just by sheer luck, nobody was hurt.

“This is completely unacceptable, so the Russian consulate will have to leave. They will have one more, and if these attacks continue, we’ll take further action.”

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.

The Russian government on Monday vowed to respond to Poland’s move to shutter the consulate in Krakow.

“Warsaw deliberately seeks to ruin the relations, by acting against its citizens. An appropriate response to these inadequate steps will follow soon,” Russian Foreign Ministry spokeswoman Maria Zakharova told state-owned news agency TASS.

Joe Stanley-Smith contributed reporting.