A huge cloud of volcanic ash from Iceland left millions of air travellers stranded Saturday as it spread further across Europe, leaving airlines grounded and facing huge losses.
After Friday saw some 16,000 flights cancelled by the drifting dust amid the biggest airspace shutdown since World War II, air traffic controllers warned that the cloud was likely to cause fresh travel disruption.
Either full or partial airspace closures were still in force in several European countries, after the previous day saw more than 15 countries implement flight restrictions.
Holidaymakers, celebrities and politicians alike had to turn to overcrowded trains, boats and taxis Friday.
Justifying the widespread airport closures aviation officials have explained that airplane engines could become clogged up and stop working if they tried to fly through the ash.
In the past 20 years, there have been 80 recorded encounters between aircraft and volcanic clouds, causing the near-loss of two Boeing 747s with almost 500 people on board and damage to 20 other planes, experts said.
The International Air Transport Association warned the fallout from the eruption of the Eyjafjallajokull volcano in southeast Iceland was costing airlines more than 200 million dollars (230 million euros) a day.
It would stop paying salaries to staff "after two weeks if the situation continues and normal working is prevented," it said in a statement.
Scandinavian airline SAS warned Friday it would temporarily lay off up to 2,500 employees in Norway starting Monday if flights remained grounded.
Smoke and ash continued to spew out of the volcano Friday, building up the cloud, which then blew east to stretch from the Atlantic to the Russian capital Moscow and from the Arctic Circle south to Bulgaria.
Eurocontrol said only 12,000 of the daily 28,000 flights in the affected zone would take off Friday, after about 6,000 were cancelled the day before.
Austria, Belgium, Britain, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Hungary, Latvia, the Netherlands, Poland, Romania, Slovakia, Spain, Sweden and Switzerland shut down all or most of their airspace.
Britain extended its flight ban until 1:00 pm (1200 GMT) Saturday and airports, including London Heathrow, the world's busiest international air hub, were deserted as operators warned travellers not to turn up.
Italy's civil aviation authority announced airspace across the north of the country would be shut down for eight hours on Saturday as the ash cloud passed.
Budget airline Ryanair cancelled all its flights in northern Europe and the Baltics until 1200 GMT Monday.
Germany closed all its airports Friday, forcing flag carrier Lufthansa, Europe's biggest airline, to cancel all its flights.
The Eurostar Channel tunnel rail service reported thousands of passengers rushing to get places on its London-Paris trains. It laid on three extra trains, but still could not keep up with demand.
The shutdown also played havoc with diplomatic schedules.
Poland had considered delaying Sunday's funeral of president Lech Kaczynski because the cloud threatened the flights of US President Barack Obama and other world leaders, but a senior presidential aide insisted it would go ahead.
German Chancellor Angela Merkel was stranded in Lisbon, Portuguese President Anibal Cavaco Silva in Prague and a UN Security Council delegation cancelled a trip to the Democratic Republic of Congo that would have flown out of Paris.
The volcano on the Eyjafjallajokull glacier erupted on Wednesday, sending ash drifting towards Europe at an altitude of about eight to 10 kilometres (five to six miles).
Source: AFP Global Edition