LONDON — The miasma of volcanic ash hovering over Europe showed no sign of dissipating Saturday, keeping thousands of forlorn travelers stranded across the continent for a third day and worsening economic losses.

The cloud of grit from the still-erupting Eyjafjallajokull volcano in Iceland began creeping as far south as Italy, forcing authorities to shut down airports in the northern part of the country.

Travelers anchored to Earth continued their scramble for hotels, or for trains, ferries and taxis to reach their desired destinations. In Copenhagen, an enterprising cab company posted fares for long hauls across the continent: about $2,000 for passengers going to Amsterdam; $6,000 all the way to Madrid.

Trade and tourism losses mounted for a region already struggling to get out from under the thumb of the global recession.

Perishable foodstuffs marked for export sat untouched in warehouses, while roses and other fresh flowers from as far away as Africa and Asia were in danger of wilting and dying before reaching European markets.

In Britain, there were reports of shortages of a few items on supermarket shelves, including certain fruits. The country imports much of its fruits and vegetables, the bulk of which arrives by sea but a portion of which is flown in.

Most of British airspace remained closed. Planes were grounded until 1 p.m. today at the earliest, despite a brief window of opportunity for a few flights Saturday afternoon from airports in Scotland, Northern Ireland and northern England. By Saturday evening, the volcanic pall covered the whole country once again.

In Germany and northern France, including Paris, authorities canceled all flights until early today . Irish, Belgian, Dutch, Austrian and Swiss airspace was restricted. Most major airports throughout Scandinavia were idled, including Arlanda, Stockholm’s largest, which warned on its Web site, “The forecast is now even more uncertain than before.”

Around the world, anxious passengers have told stories of missed weddings, business deals and holidays because of the ominous plume. Stranded passengers reported the delays were causing financial hardships. Some had to check out of hotels and sleep in airports.

“It’s like a refugee camp,” said Rhiannon Thomas of Birmingham, England, describing the scene at New York’s Kennedy Airport.

As far away as Singapore, the backup of international passengers was so bad that hotel rooms were becoming hard to find in the city-state.

U.S. troops injured in Iraq and Afghanistan were being flown directly to Andrews Air Force Base for treatment in the United States rather than to Landstuhl Regional Medical Center in Germany, the usual first stop for the wounded. Military planes unable to land in Germany because of the volcanic ash will refuel in midair or in Italy, Pentagon spokesman Bryan Whitman said.

With the pileup of marooned passengers growing by the hour, and with U.S. airlines canceling more than 80 percent of their flights to Europe on Saturday, analysts say that clearing out the backlog and getting the system back to normal could take days once the ash cloud dissipates.

Scientists say that because the volcano is below a glacial ice cap, the magma is being cooled quickly, causing explosions and plumes of grit that can be catastrophic to plane engines, depending on prevailing winds.

And no one was predicting when the cloud would clear.

“It’s still erupting,” Armann Hoskuldsson, a scientist at the University of Iceland, said of the volcano. “It’s more or less constant.”

In Iceland, winds dragged the ashes over new farmland to the southwest of the glacier, causing farmers to scramble to secure their cattle and board up windows.

With the sky blackened out and the wind driving a fine, sticky dust, dairy farmer Berglind Hilmarsdottir teamed with neighbors to round up her animals and get them to shelter. The ash is toxic — the fluoride causes long-term bone damage that makes teeth fall out and bones break.

“This is bad. There are no words for it,” said Hilmarsdottir, whose pastures near the town of Skogar were already covered in a gray paste of ash.

As winds blew the volcanic debris farther south and east, previously unaffected countries in Central and Eastern Europe, stretching as far as Ukraine, also began reporting a halt to air traffic.

The airline industry stands to lose more than $200 million a day, according to the International Air Transport Association. The European aviation agency Eurocontrol said it expected only 5,000 flights across European airspace Saturday, compared with 22,000 normally.

Additional material from The Associated Press and The Washington Post.