Poland and Ukraine denounced Russian strikes close to the Polish border that hit a Warsaw-bound train near a frontier checkpoint yesterday just after another train carrying several EU officials and former British prime minister Boris Johnson passed through.
Ukraine's rail operator said Mr Johnson and former US CIA director David Petraeus, who were in Kyiv for the annual Yalta European Strategy forum, had been travelling on two separate trains around the time the Warsaw-bound locomotive was hit.
Mr Petraeus told the New York Times in a telephone interview yesterday that he could hear Russian drones above followed by an explosion - prompting passengers to be quickly evacuated.
"For those who have not been under fire, this was terrifying... This is the act of a truly barbaric leader trying to terrorise Ukrainian civilians," he added.
Mr Johnson, who was travelling with several EU officials in a separate train, condemned the attack in a post on X.
"I don't know what warped logic drove Putin to blow up a stationary Ukrainian locomotive on the Polish border this morning," he said.
"What we can say for sure is that this is the kind of random and senseless attack Ukrainians are enduring every day - even on civilian railways."
Poland and Ukraine said a Kyiv-Warsaw passenger train was struck just 2km (1.2 miles) from the Polish border, but reported no casualties.
Warsaw has been one of Kyiv's main allies and, with Ukrainian airspace closed, trains to Poland have been one of the main routes out of the war-torn country, used by refugees.
The Ukrzaliznytsia rail operator confirmed the attack yesterday but did not say how far the officials were from the strike site.
"A diplomatic train was at Yagodyn station... among others, security advisers from several EU member states and former European leaders (were) on board, including former UK prime minister Boris Johnson," the operator said.
"In another train that was at Yagodyn station at the very moment of the attack was former CIA director David Petraeus."
Trump calls on Zelensky to halt attacks on Russian refineries
The strikes came as US President Donald Trump called on Ukraine's President Volodymyr Zelensky to halt attacks on Russian refineries, saying it was causing a shortage of diesel fuel and "there are plenty of other targets".
Ukraine has increasingly targeted Russian oil refineries in a bid to hurt Russia's war effort.
Russia attacked western Ukraine with drones yesterday, just days after US envoys visited Kyiv and Moscow in a bid to revive talks to end the war.
Mr Zelensky said Moscow "deliberately" struck the locomotive.
"It is precisely to prevent these strikes from spreading further into Europe that Ukrainian men and women fight every day, give their lives, and do not allow the aggression to expand," Mr Zelensky said.
Poland's Prime Minister Donald Tusk chaired an emergency meeting in Warsaw following the strikes, warning he expected Russia to escalate the war "in the coming weeks".
He added: "We cannot exclude that the escalation will also affect our territory... I hope not."
Russia said it had hit "railway infrastructure used to transport military cargo" from European countries.
Escalation should lead allies to double support - foreign minister
Speaking in Kyiv, Poland's foreign minister Radoslaw Sikorski said the "escalation" should lead to allies to "double" their support for Ukraine.
"This was just a few hundred metres from the Polish border, this affects the safety of my countrymen," Mr Sikorski said.
Ukraine's Foreign Minister Andriy Sybiga said Russian President Vladimir Putin considered Russia was "de facto" at war with Europe.
"Putin's terror is literally knocking at the door of the European Union and NATO," Mr Sybiga said.
Russian attacks killed at least two people yesterday in the frontline city of Kramatorsk.
Twenty people, including two children, were also wounded in a second day of attacks on the southern port city of Odesa, Ukrainian officials said.
Meanwhile, the Kremlin said negotiations with Ukraine and the US on the war could take place in October.
"We do not rule out such a possibility; we are talking about the foreseeable future," Kremlin spokesman Dmitry Peskov told journalists, cited by Russia's Ria and Tass news agencies.
Several rounds of negotiations have failed, while US-led efforts stalled during the Middle East war.
In an interview released on Saturday, Mr Zelensky said he would be willing to meet Mr Putin at the G20 summit in Miami in December.
But Mr Peskov said that was "impossible", speaking in New Delhi on Saturday, repeating Moscow's demand that a meeting could only take place in the Russian capital.