A cloud of volcanic ash still lingers over Europe, wreaking havoc on European air travel by forcing the extension of no-fly restrictions, as scientists warn that activity at a volcano in Iceland is increasing.

Scientists in Iceland said Saturday that activity at the Eyjafjallajokull volcano has increased, sending yet more grit into the air that can be extremely dangerous for plane engines.

"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."

A combination of light prevailing winds and large amounts of unmelted glacial ice above the volcano has led forecasters to warn that the situation is unlikely to change in the next few days.

The ice cools the magma quickly, causing explosions and plumes of grit, such as the ash cloud, that can prove catastrophic for plane engines. Only about a third of the total amount of glacial ice above the volcano has reportedly melted.

Bill Burton, a scientist with the U.S. Geological Survey, told CTV News Channel that the Eyjafjallajokull volcano last erupted in 1821, when the eruption lasted for longer than a year.

"If this volcano has a history of past lengthy eruptions, it's reasonable to expect that this one will be as well," he said Saturday.

Scientists said the ash cloud that now hovers over parts of western Europe continued to travel south and southeast Saturday, grounding yet more flights.

European air navigation safety agency Eurocontrol said only about 5,000 flights will take off Saturday. Under normal circumstances, about 22,000 flights take place.

Flight cancellations are also affecting travel at Canadian airports: all departures from Toronto, Montreal, Ottawa, Edmonton and Vancouver to northern Europe were cancelled Saturday. The same was true for arrivals in those cities from northern Europe.

Because of the flight cancellations and restrictions, the aviation industry is facing at least $200 million in losses every day, according to the International Air Transport Association.

Scandinavian airline operator SAS AB has given temporary layoff notices to as many as 2,500 ground staff as a precautionary move. Other airlines are considering similar action if the flight restrictions continue.

The restrictions have stranded thousands of travellers, many of whom have turned to trains, buses, ferries and even taxis to try and get home.

The flight restrictions have also left a number of world leaders with no choice but to cancel plans to travel to Warsaw for the state funeral of Polish President Lech Kaczynski and his wife Maria.

Prime Minister Stephen Harper cancelled his trip to the funeral around mid-day Saturday as the volcanic ash forced more flight restrictions across Europe.

The Canadian delegation had been scheduled to fly out of Ottawa early Saturday. Before the cancellation was announced, their departure had been pushed back to 3 p.m. ET.

Delegations from Britain, Germany, India, Japan, South Korea, Mexico, New Zealand and Pakistan have also cancelled plans to attend the funeral, as has U.S. President Barack Obama.

The delays and cancellations squeezed the wallets of average travellers who had tried to sleep in hotels but were forced to check out and sleep in 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," Anthony Adeayo, 45, who was due to travel from Britain to Nigeria with British Airways, told The Associated Press.

The volcano began erupting Wednesday for the second time in the past month, sending a plume of ash several kilometres into the air. Winds have sent the cloud travelling south and east over Britain, Ireland, Scandinavia and parts of Europe.

Airspace closures include:

• U.K. airspace is closed until at least 6:00 a.m. GMT Sunday (2 a.m. EDT Sunday), and British Airways has cancelled all flights to and from the U.K. on Sunday.
• Ireland has closed its airspace until at least 12:00 p.m. GMT on Sunday (8 a.m. EDT).
• Airports in Paris and about 25 others in northern France are closed until 8 a.m. Monday morning (6:00 a.m. GMT).
• German airspace is closed until 2 p.m. on Sunday (12:00 p.m. GMT).
• Austrian airspace below 7,500 metres is closed until at least 12:00 p.m. GMT on Sunday. Airspace above 7,500 metres reopened Saturday evening.
• In Belgium, Brussels Airlines cancelled its flights through to noon on Monday and Belgian airspace is closed until at least 6:00 a.m. GMT on Sunday.
• Airspace in the Netherlands has been closed until further notice.
• Swiss airspace is closed until 2:00 p.m. GMT on Sunday. But planes equipped with instruments are allowed to fly above Switzerland if they remain higher than 6,000 metres (20,000 feet).
• In northern Italy, airspace is closed until 6:00 a.m. GMT on Monday.
• Until further notice, Spain's Iberia airline has cancelled its flights across Europe, except those from Spain to Portugal, southern Italy, Greece and Istanbul.
• Sweden's airspace has also been closed until further notice. Denmark's is shut until 6:00 a.m. GMT at the earliest. Finland's airspace is closed until 12:00 GMT on Sunday. The airspace in Norway's far north remains open and 21 small airports are operating there.
• Bosnian airspace is closed until early Sunday at the earliest.
• Czech Republic has closed its airspace until at least noon on Sunday.
• Croatia's international airports in Zagreb and Osijek are closed, as are those in western areas of the country.
• Slovenia's Maribor and Portoroz international airports are not operating.
• In Serbia and Montenegro, airspace is closed until further notice.
• Belarus has announced that all flights are banned until 1:00 p.m. GMT at the earliest. Most European flights have been cancelled at Minsk National Airport.
• All airports in the Ukrainian are shuttered airports until further notice. The airport in Simferopol in Crimea is an exception.
• Close to 200 flights from Russian airports have been delayed or cancelled.
• Australia's Qantas airline has announced that its flights from Australia to Europe via Asian cities would not travel beyond the Asian stops on Saturday and Sunday.
• Air New Zealand has cancelled its flights to London for the second day in a row. About 2,000 people are waiting to depart that country.

With files from The Canadian Press and The Associated Press