Stranded travelers slept on makeshift beds at European airports Sunday as wintry weather caused travel havoc, dashing the hopes of those attempting to head away for the holidays by road, rail and air.

It is almost inevitable that some cancelations and delays will continue through this week, potentially causing further disruption for many Christmas travelers, British travel industry group ABTA said.

Heathrow Airport, Europe's busiest hub for air passengers, stopped accepting arrivals Sunday at the start of the Christmas travel rush.

"The domino effect of disruption to services could continue for some days to come," Heathrow spokesman Andrew Teacher said.

Icy conditions curtailed Europe's high speed train services, left cars skidding through slushy streets and saw major events postponed — including music shows and sporting events.

In Paris, a Lady Gaga concert was canceled because trucks delivering sets for the pop diva's extravagant event couldn't get to the city's Bercy stadium. The show was expected to be rescheduled for Tuesday.

British pop star Lily Allen was among those caught in the travel chaos in London, where several thousand people spent the night on the floors of terminal buildings at the city's major airports. "Bad start to a much needed holiday," Allen said in a post on her Twitter account after her flight was canceled.

About 40 percent of flights were canceled at Frankfurt airport and at Paris' Charles de Gaulle.

Passengers slept in makeshift dormitories at the Paris airport and at Amsterdam's Schiphol, while staff at Heathrow and Gatwick airports in London handed out foam mats and foil blankets to the stranded. Some fashioned improvised beds from clothes, chairs and stacked suitcases.

"Dad are we in Argentina yet?" one elementary school child sobbed, as his father bought sandwiches, playing cards and comic books from a store inside a Heathrow terminal building.

Janos Kalman, a 50-year-old psychiatrist from Szeged in Hungary, said he had braved a night on a terminal floor at Heathrow after his flight to Budapest was canceled. "I've seen people crying and panicking, and the staff trying to cope with it all," he said.

London subway trains were packed with dejected holiday travelers in search of hotel rooms, while many tourists complained there was little clear information amid the chaotic scenes at the city's airports.

"There seems to be a lot of confusion and I have only seen one Heathrow worker. All the airline desks are shut because it is a Sunday — it's absolutely ridiculous," said Elizabeth Herridge, who arrived at the airport to learn her flight to Amsterdam had been canceled.

Airports and tour operators acknowledged there would likely be some disruption to flights through next week, with many aircraft currently stuck in the wrong location.

"Inevitably there is always some knock-on effect when there's a situation like this. People will need to consult with their airlines next week to check on their flights," said Sean Tipton, spokesman for Britain's ABTA.

However, he said the disruption caused by Europe's blast of icy weather was minor compared to the chaos triggered by the giant ash cloud spewed from Iceland's Eyjafjallajokull volcano earlier this year. "To those people caught up in the disruption that's not going to be much consolation," Tipton said.

Britain's national weather forecaster, the Met Office, said the nation has experienced the heaviest snow falls in December in decades and is on course for record low temperatures.

"You have to look back to December 1981 to find similar snow depths," forecaster Helen Chivers said. "If the second half of the month is as cold as the first, this will be the coldest December on record since 1910."

France is also having one of its snowiest winters in years. Many TGV fast trains were running slower than usual, tacking about 20 minutes on to each journey. Eurostar trains to Britain and Thalys trains to Belgium and the Netherlands were also affected.

French weather service Meteo France said it forecasts more snow for the Paris region for Monday and a risk of snow and ice in Paris on Dec. 26 — another major travel day.

Lady Gaga's canceled concerts in Paris had already been rescheduled — it was originally postponed in October during massive strikes in France.

The pop star said staging and sound equipment was stuck aboard heavy trucks ordered off the city's roads during the icy weather. "I am furious and devastated, it's unfair to my fans and to me," she wrote on her Twitter site.

In Italy, Florence's airport remained closed Sunday morning amid snow and ice storms that blanketed Tuscany. At Frankfurt airport, Germany's biggest, more than 500 flights were canceled Sunday out of a planned total of 1,330 departures and arrivals.

Temperatures dipped to below -20 C (-4 F) in some parts of Scandinavia, where meteorologists warned snow was piling up on the icy roads following heavy snowfall and strong winds. Airports were operating normally, but several long-distance trains were delayed.

Soccer games in England, Scotland, France and the Netherlands were called off as a result of the conditions, including a high-profile match scheduled for Sunday in London between Chelsea and Manchester United.

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Angela Doland in Paris, Sheila Norman-Culp in London, Geir Moulson in Berlin, Malin Rising in Stockholm, Nicole Winfield in Rome and Mike Corder in the Hague, Netherlands, contributed to this report.