Professor Katarzyna Pisarska, chair of the Warsaw Security Forum, told the BBC she was in the same carriage as Johnson and Powell, and the attack had happened about 30 minutes after their train had crossed into the Polish border. In a statement, Ukraine's railway authority Ukrzaliznytsia said the diplomatic train "had left the station earlier than expected because of the timetable change...

It also said that an evacuation order for passengers on the hit train had been given "just 15 minutes" before the strike by a Russian jet-propelled drone. In an interview with the New York Times, Petraeus said: " This is the act of a truly barbaric leader trying to terrorise Ukrainian civilians."

2 miles) from the Polish border. Ukraine said strikes had continued overnight, with the country's air force reporting that 85 of 108 Russian drones that were launched had been shot down.

Police in Chernihiv said on Monday morning that three people had died after a warehouse belonging to an agricultural business was struck in Pryluky. Russia's defence ministry also reported that nearly 400 Ukrainian drones had been destroyed over Russian regions overnight.

Russia appears to be escalating its war against Ukraine by targeting trains, railway depots, petrol stations and border crossings. Earlier this week, two people were killed when Russian drones hit a border crossing between Ukraine and Moldova, Ukrainian President Volodymyr Zelensky said.

Also this week, a female conductor died in a Russian drone attack on a passenger train in southern Ukraine. Six Ukrzaliznytsia employees were killed after a depot was struck in Kyiv at the start of the month.

In January, Zelensky condemned as "terrorism" a Russian strike on a crowded passenger train in the north-eastern Kharkiv region that left five people dead. The Russian attacks have significantly damaged Ukraine's vast train network - the main mode of transportation for millions of Ukrainians as all air travel has been suspended since the start of Russia's full-scale invasion in 2022.

European countries are also blaming Russia for suspicious incidents on their territory. There have also been a number of suspicious fires at defence facilities from Italy to Estonia, with some of the affected countries blaming Russia.

Russian authorities have also accused Ukraine of targeting trains and busses in recent months. The Crimea bridge - also known as Kerch Bridge - was built by Russia after it invaded and annexed the Crimean Peninsula in 2014.