As Westerners scramble to get out of Ukraine, airlines have been cancelling and diverting flights in and out of Kiev.
An estimated 130,000 Russian troops are massed on the borders, with fears of an imminent invasion.
On Saturday the UK government urged: “British nationals in Ukraine should leave now while commercial means are still available.”
But the Dutch carrier KLM cancelled its flights between Amsterdam and the Ukrainian capital, leaving passengers to find their own flights.
Tim White, a journalist specialising in Ukraine, was booked on the flight.
He tweeted: “Trying to follow UK Govt instructions, managed to bag a place on KLM flight tomorrow for inflated price. Now they tell me it’s ‘disrupted’.
“It’s cancelled, stranding passengers in a war zone. There is an Air France flight but won’t let me rebook.”
An email from KLM telling him about the disruption read: “At present, it’s not possible to offer you an alternative flight.”
Under European air passengers’ rights rules, any airline cancelling a flight is required to find, and pay for, an alternative departure.
Mr White eventually bought a new flight on Austrian Airlines via Vienna.
The Independent has asked KLM for a response.
Early on Sunday, a holiday jet from Madeira to Kiev was diverted to Chisinau in neighbouring Moldova because the leasing company refused to let it enter Ukrainian airspace.
SkyUp flight PQ902 was due to arrive in Kiev at 3.50am on Sunday. But the company that owns the Boeing 737 aircraft told the airline that it could not land as scheduled. The plane landed at Chisinau, 250 miles southwest of Kiev, at 3.30am. Passengers were eventually bussed to the city.
According to Flightradar24 the aircraft is still on the ground in the Moldovan capital.
The Ukrainian government has promised more than £450m in insurance cover from its emergency reserves to try to persuade airlines to keep flying.
Meanwhile airlines are giving Ukraine a wide berth on flights between Europe and Asia.
The most direct tracks from London to Delhi and Singapore, and from Manchester to Mumbai, include almost the full length of Ukraine.
Many carriers have steered clear of eastern Ukraine since 2014, when Malaysia Airlines flight MH17 was downed by a Russian anti-aircraft missile fired from rebel-held territory.
All 298 people on board the Boeing 777 died.
On Saturday a British Airways captain flying from London Heathrow to Bangkok tweeted a map of the flight plan, which took a very southerly course over Egypt rather than Ukraine.
“A long flight time today at 12h12m for our freighter from LHR to BKK,” he wrote. “Current geo-politics making itself felt on the flight plan.”
