Although the ash plume has grown, a northerly wind was expected to allow enough visibility for scientists to fly over the volcano Saturday. Scientists want to see how much ice has melted to determine how much longer the eruption could spew ash. Because the volcano is situated below a glacial ice cap, the magma is being cooled quickly, causing explosions and plumes of grit that can be catastrophic to plane engines if prevailing winds are right.

"The activity has been quite vigorous overnight, causing the eruption column to grow," Icelandic geologist Magnus Tumi Gudmundsson told The Associated Press on Saturday. "It's the magma mixing with the water that creates the explosivity. Unfortunately, there doesn't seem to be an end in sight."

An expansive cloud of grit hovered over parts of western Europe on Saturday, triggering extended flight bans that stranded people around the globe. Continued volcanic activity could produce more plumes if the weather patterns stay the same.

Aviation experts say the volcanic plume has caused the worst travel disruption Europe - and the world - has ever seen.

"I've been flying for 40 years but I've never seen anything like this in Europe," said Swedish pilot Axel Alegren, after landing his flight from Kabul, Afghanistan, at Munich Airport; he had been due to land at Frankfurt but was diverted.

Anxious passengers have told stories of missed weddings, graduations, school and holidays because of the ominous plume, which seemed likely to disrupt world leaders' plans to attend Sunday's state funeral for Polish President Lech Kaczynski and his wife Maria in the southern city of Krakow.

So far, delegations from India, Japan, South Korea, Mexico, New Zealand and Pakistan have canceled plans to attend the state funeral. President Barack Obama, Russian President Dmitry Medvedev and German Chancellor Angela Merkel still planned to attend.

On Saturday, the French prime minister extended the closure of airspace in northern France until Monday morning. British and German officials closed until 0000 GMT (8 p.m. EDT). The Belgian, French and Swiss governments extended their ban until Saturday evening.

Stranded passengers reported the delays were causing financial hardships. Some had to check out of hotels and sleep in the airports.

"I have been staying in a hotel but have now checked out and do not know what I am going to do - I have limited financial resources here," said Anthony Adeayo, 45, who was due to travel from Britain to Nigeria with British Airways.

Eva Macieyow, 33, said she had been due to depart for Germany with a friend.

"We are a little frustrated," she said. "Last night we thought we had a flight ... but now it has been canceled and we know nothing."

Shoppers were warned Saturday that continued flight bans could spark shortages of imported fresh fruit and vegetables.

"There are no shortages yet, but we may start to see certain ranges affected if this carries on," said Christopher Snelling, head of global supply chain policy for the Freight Transport Association.

Italian aviation authorities were closing airspace in northern Italy on Saturday until midday (1000 GMT; 6 a.m. EDT), with airports in Milan and Venice to close.

Denmark and Finland's airspace also remained closed, while Norway and Sweden said some air space in the far north could be opened as the cloud moves south. Air space in the central and southern parts of the Nordics was expected to remain closed at least until Sunday afternoon.

Serbia also closed a small strip of its airspace in the north of the country and said it could close more later. Belarus and Ukraine introduced closures and restrictions.

Australia's Qantas canceled all flights to Europe on Saturday, and passengers were being offered refunds or seats on the next available flight. The airline said it was not known when flights would resume. Cathay Pacific was already canceling some Europe-bound flights leaving Hong Kong on Sunday.

"The British Airways telephone message says check the Web site for updates but when you check the site it says call the customer services number," said James Kirkman, 41, who was visiting family in Australia with his two kids. "There's no information. The kids were due back at school on Monday."