Polish Prime Minister Donald Tusk on Friday denounced what he said was Russian "state terrorism" after the sabotage of a railway line used to deliver aid to neighbouring Ukraine.
In a brief address to parliament, Tusk called on Poles to unite against Moscow's attempts to "sow discord with Europe, with Ukraine, and, above all, among ourselves".
"Diversionary acts inspired and organised for months by Kremlin services have recently crossed a critical line, and we can now even speak of state terrorism," he said.
Tusk claimed their goal was to "destroy human life and destabilise the foundations of the Polish state."
Between Saturday and Monday, a clamp was attached to a track -- likely intended to cause a derailment -- while an explosive device was detonated along the track as a freight train passed.
Warsaw has identified two Ukrainians suspected of acting on behalf of Moscow as the alleged perpetrators and has asked Belarus, an ally of Russia where the two men are believed to have fled, to extradite them.
The Belarusian Ministry of Foreign Affairs on Friday announced that its law enforcement, in cooperation with Polish counterparts, is "actively searching" for the suspects.
"The competent authorities are conducting joint activities to establish the whereabouts of two Ukrainian citizens suspected of committing terrorist crimes on Polish territory," the Ministry stated.
Poland also announced it would close the last remaining Russian consulate in Poland still in operation, in the port city of Gdansk.
Moscow on Tuesday denounced Polish claims about its involvement, accusing Warsaw of "Russophobia".
In his address, Tusk urged lawmakers not to repeat pro-Russian narratives, reminding them of a large-scale disinformation campaign that has tried to shift the blame onto Ukraine.
"Support Ukraine in its war against Russia without any 'buts'," he told parliament.
Tusk called upon nationalist and far-right opposition MPs, as well as Poland's conservative-nationalist president and his office, not to call European unity into question.
"Support a strong West, not Russia," the prime minister insisted.
"During war, there are no 'buts'; either you're for Poland or against it, especially when it comes to national security in the face of the Russian threat," Tusk added.
