Air travel throughout Europe and around the world is still disrupted Saturday as thick clouds of ash from a volcano eruption in Iceland continue to drift across the continent.
Some European nations have completely closed their airspace, while others have enacted partial closures. Thousands of flights have been canceled, stranding hundreds of thousands of passengers and costing airlines hundreds of millions of dollars. Officials expect air travel to be disrupted for several days.
Rail services, ferries and taxi companies in Europe say they have seen a huge increase in customers as a result of the disruptions.
The ash clouds include particles of rock, glass and sand that pose a serious threat to aircraft.
In addition to the travel problems, officials are urging people with breathing problems to stay indoors.
The shutdown of air travel is the most extensive since the terrorist attacks in the United States on September 11, 2001.
World leaders are among those whose travels have been affected. German Chancellor Angela Merkel was not able to make it home from her visit to the United States, and spent the night in Lisbon, Portugal.
There is also concern about whether world leaders, including U.S. President Barack Obama and Russian President Dmitri Medvedev, will be able to get to Krakow for Sunday's funeral of Poland's late president, Lech Kaczynski.
Wednesday's eruption of the volcano in southeastern Iceland is its second since March 20. The volcano had been dormant for nearly 200 years. Experts say it could continue to erupt for weeks or even years.