Ash from a volcano that erupted in Iceland caused Norway, Sweden and Denmark to close their airspace Thursday, while Finland halted most air trafic, authorities said.

• Iceland volcano blast could last 'long time'
• Iceland volcano ash brings European air chaos

All Norwegian airspace was closed Thursday, and Transport Minister Magnhild Meltveit Kleppa told reporters the "airspace will be closed tomorrow too, and the outlook for the next two-three days is not good."

The Scandinavian country was the first to shut down part of its airspace Wednesday, citing the risk posed by volcanic ash blown in from Iceland.

The airspace closure left Norwegian Prime Minister Jens Stoltenberg stranded in New York and Norway's Crown Prince Haakon stuck in London, according to the NTB news agency.

All flights to Norway's North Sea oil and gas platforms had also been cancelled, but production had yet to be affected, NTB reported.

"We have ... concluded that this will not have any immediate consequences for production," Gisle Johansson, a spokesman for Norwegian oil giant Statoil, told NTB.

Neighbouring Sweden also started shutting down airspace in the north of the country late Wednesday, eventually announcing Thursday that all air trafic would be grounded by 2000 GMT.

"We are closing airspace sectors one by one and we are following the ash cloud ... It's coming from the northwest" of Sweden, LFV aviation authority spokesman Carl Felling told AFP.

Denmark meanwhile said its entire airspace would be shut by 1600 GMT.

Copenhagen's international airport Kastrup, the most important in the Nordic region, was to close at 1430 GMT until at least 1000 GMT Friday, airport spokesperson Soeren Hedegaard Nielsen told AFP.

Air traffic was also restricted in most of Finland, although the main airport in the capital Helsinki was still operating.

Both Norway and Finland's state rail companies promised to set up extra trains Thursday to help transport passengers stranded by the grounded flights.

Iceland's second volcano eruption in less than a month began under the Eyjafjallajokull glacier in the south of the country at around 1:00 am (0100 GMT) Wednesday.

The eruption sent a huge ash cloud across Northern Europe, prompting airspace closure in Britain, Ireland, the Netherlands, Belgium and hundreds of flight cancellations worldwide.

Icelandic airports, however, reported no problems.

"The wind is blowing the ash to the east," Hjordis Gudmundsdottir of the Icelandic Airport Authority told AFP, adding: "It's amazing really."