The Russian military on Sunday attacked a passenger train in Ukraine's border region with Poland using a combat drone, with Ukraine's rail company later speculating that Western diplomats and former politicians might have been the target.

"The escalation from the Russian side has now become a reality and the examples of it are coming ever closer to our border," Polish Prime Minister Donald Tusk said at a meeting of the crisis team following the incident.

"Putin escalates," Polish Foreign Minister Radosław Sikorski wrote on X.

On Sunday, the locomotive of the regular 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. Western politicians travelling to Kiev also rely on the rail link from Poland to Ukraine as the country's airspace is closed.

The Ukrainian railway company said in the evening that shortly before the attack a diplomats' train had stopped at Yahodyn station carrying, among others, security advisers from several EU countries and former senior European politicians, including Boris Johnson, who was the UK prime minister in February 2022 when Russia launched its full-scale invasion of Ukraine. The group had attended a conference in Kiev the day before.

Another train standing at the station at the time of the attack reportedly carried former CIA chief David Petraeus.

"It is entirely conceivable that the target of this Russian drone could also have been the diplomats' train which, as part of real-time timetable adjustments due to the constant threat of Russian attacks, departed from the station earlier than originally planned," the railway company wrote on Telegram. Timetables were constantly being adjusted because of the war, it said.

Johnson said the Russian attack is yet another example of how Russia is conducting itself in this war.

"I don't know what warped logic drove Putin to blow up a stationary Ukrainian locomotive on the Polish border this morning," Johnson wrote on X. "What we can say for sure is that this is the kind of random and senseless attack Ukrainians are enduring every day." He did not comment on reports that he had been on another train near the attack.

The Defence Ministry in Moscow confirmed attacks on rail infrastructure in western Ukraine that facilitated transport of military goods from European countries, it said.

Due to the threat of airstrikes, two border crossings on the Polish side temporarily suspended operations. Several hundred people were evacuated for a short time. By the afternoon, the situation at the border had normalized again.

Tusk pointed out that Russia had previously attempted to paralyse border crossings in Moldova. Allies had given indications beforehand that the Russian plan would include attempts to disorganize and possibly destroy Ukrainian border crossings and this could also affect Poland. More intense Russian action was to be expected in the coming weeks and months, Tusk said.

Ukrainian President Volodymyr Zelensky wrote earlier 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 for 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.

Johnson criticized Western powers for what he sees is a lack of support for Ukraine

"When are we going to give them the air defences they need? Why won't we unfreeze Putin's cash and give it to Ukraine? There is more than 140 billion euro ($163 billion) in a Belgian bank account - and about £10 billion ($13.5 billion) in London. Britain could show a lead," the former British prime minister asserted.

Ukraine has been defending itself against a Russian invasion for more than four and a half years with Western help. Russian attacks repeatedly cause deaths and damage to rail traffic and at stations.

FILE PHOTO: Then UK Prime Minister Boris Johnson speaks to media upon his arrival to attend a NATO summit in Madrid. (is associated with: «Poland alarmed after Russia attacks train from Kiev to Warsaw») Bernd von Jutrczenka/dpa
FILE PHOTO: Then UK Prime Minister Boris Johnson speaks to media upon his arrival to attend a NATO summit in Madrid. (is associated with: «Poland alarmed after Russia attacks train from Kiev to Warsaw») Bernd von Jutrczenka/dpa