Freezing weather has hit transport hubs across Europe, closing airports, blocking roads and halting trains.
London's Heathrow cancelled 30% of flights on Sunday and dozens of flights were delayed at Amsterdam's Schiphol, the BBC reports.
Transport hubs in Central and Eastern Europe have been forced to close amid the biggest freeze in decades, which has claimed more than 200 lives.
In Bosnia, officials have declared a state of emergency in Sarajevo, where snow has paralysed the city, while in Serbia a state of emergency is in place across much of the country.
In Italy, canals in Venice have begun to freeze over, and the capital Rome has seen its most severe snowfall in more than 25 years.
Thousands of people are said to be trapped in their homes across both countries and many travellers have been stranded.
Ukraine has been hit hardest by the weather, recording more than 100 deaths so far.
Forecasters predict the freeze will ease in Ukraine, though parts of the country will still be enduring temperatures as low as -19C.
The Siberian weather system has brought heavy snow and temperatures plummeting to below -30C in parts of Central and Eastern Europe.
The spike in energy demand forced Russian gas supplier Gazprom to reduce its deliveries to Europe over the past few days.