After Russian attacks on a train from Kiev to Warsaw and on Ukraine's border region with Poland, the Polish government on Sunday accused Moscow of escalating the conflict.
"Putin escalates," Foreign Minister Radosław Sikorski wrote on X.
Prime Minister Donald Tusk held a crisis meeting of cabinet ministers and uniformed services Sunday afternoon.
Western politicians travelling to Kiev rely on the rail link from Poland to Ukraine as the country's airspace is closed.
"The escalation on the Russian side has now become a reality, and the examples of this are coming ever closer to our border," Tusk told the meeting.
On Sunday, the locomotive of the passenger train from Kiev to Warsaw was attacked at the border station of Yahodyn, according to Ukrainian Railways. Passengers were evacuated in time and nobody was harmed, it said.
Polish railway operator PKP said it had taken over the train from the Ukrainian side with a delay of more than six hours and it was continuing on to Warsaw.
Poland's Defence Minister Władysław Kosiniak-Kamysz said a drone also struck in western Ukraine one kilometre from Poland's border and another at a distance of five kilometres. Polish F-16 fighter jets and a reconnaissance aircraft monitored the situation, he said. Polish airspace was not violated.
By the afternoon, the situation at the border had reportedly returned to normal.
Expect more incidents, says Tusk
Tusk pointed out that Russia had already attempted to paralyse border crossings in Moldova in the past. Allies had previously provided information suggesting that the Russian plan would involve attempts to disrupt and possibly even destroy Ukrainian border crossings - a situation that could also affect Poland.
We must expect Russia to step up its activities in the coming weeks and months, Tusk continued. "We cannot rule out that this escalation will also affect our national territory." He warned that Russia was also prepared to deploy drone swarms against Poland.
Ukrainian President Volodymyr Zelensky wrote that Moscow's attacks near the Polish-Ukrainian border in the Volyn region set a locomotive on fire and damaged a petrol station.
Ukrainian Foreign Minister Andrii Sybiha called for tougher consequences on Moscow. Russian attacks on the Polish-Ukrainian border were not simply a continuation of attacks on Ukraine's state borders, he wrote on X.
"This is Putin's terror 'knocking' directly on the doors of the EU and NATO. Russian barbarians are at your gate, dear partners," he said.
"We are taking these events extremely seriously," Interior Minister Marcin Kierwiński wrote on X.
The Defence Ministry in Moscow confirmed attacks on rail infrastructure in western Ukraine that facilitated transport of military goods from European countries, it said.
Ukraine has been defending itself with Western help for more than four and a half years against a Russian invasion. Russian attacks repeatedly cause deaths and damage to rail traffic and at stations.
