Poland has accused Russian intelligence services of orchestrating a massive fire that nearly completely destroyed a shopping centre in the capital Warsaw last year.
In a post on X, Prime Minister Donald Tusk said Poland knows "for sure" that the blaze at the Marywilska shopping centre was caused by arson ordered by the Russian special services.
Some of those responsible are already in custody, Tusk added, while all the others alleged to have been involved have been identified and are being searched for.
Moscow has not commented on the allegations, but has previously denied accusations of sabotage in Europe.
The fire in May 2024 destroyed 1,400 small businesses, with many of the staff there being members of Warsaw's Vietnamese community.
Poland carried out a year-long investigation into the incident, which has now concluded the fire was organised by an unnamed person in Russia.
A joint statement by Poland's justice and interior ministers said the actions of those in custody were "organised and directed by a specific person residing in the Russian Federation."
The two ministries added that they were co-operating with Lithuania "where some of the perpetrators also carried out acts of diversion".
Since Russia's full-scale invasion of Ukraine in 2022, Poland has detained and convicted several people accused of sabotage on behalf of Russian intelligence services.
Polish officials have said that these attacks have been part of a "hybrid war" waged by Moscow.
Hybrid warfare is when a hostile state carries out an anonymous, deniable attack, usually in highly suspicious circumstances. It will be enough to harm their opponent, especially their infrastructure assets, but stop short of being an attributable act of war.
Nato also believes Russia is waging "hybrid warfare" in Europe, with the aim of punishing or deterring Western nations from continuing their military support for Ukraine.
Russia has denied repeated allegations by Nato countries that its secret services are engaged in sabotage operations across Europe.
Back in March, Lithuanian prosecutors accused Russia's military intelligence service of being behind an arson attack on a branch of Ikea in the capital Vilnius last year.
At the time, Tusk said Lithuania had confirmed Warsaw's "suspicions that [those] responsible for setting fires to shopping centres in Vilnius and Warsaw are the Russian secret services."
Two Ukrainian suspects were arrested.
