Fears of air travel chaos as Iceland volcano erupts (VIDEO)

A volcano in Iceland has erupted, shutting down the country's airspace Sunday a year after the eruption of the Eyjafjallajokull volcano caused aviation chaos across Europe.

Grimsvoetn, located at the heart of Iceland's biggest glacier, Vatnajoekull, began erupting late Saturday, sending a plume of smoke and ash as high as 12 miles into the sky.

A spokeswoman for Iceland's airport administration, Isavia, said the airspace closure "affects pretty much all of Iceland right now, at least for the next hours… Flights to and from Iceland are shutting down," Agence France-Presse reports.

Delays had already been reported for some Scandinavian trans-Atlantic flights. “We expect the ash cloud to enter Norwegian airspace over the course of the night,” Jens Petter Duestad, chief of control centers for Norwegian airport operator Avinor, told Bloomberg.

Air safety officials told AFP that ash clouds could reach northern Scotland by Tuesday and France and Spain by Thursday if the eruption does not die down.

However, Iceland's Meteorological Office said the eruption of the Grimsvoetn volcano — Iceland's most active — should not cause widespread disruption to air traffic, while the European air safety organization EUROCONTROL said no impact was expected on European airspace outside Iceland or on trans-Atlantic flights for at least 24 hours.

The Eyjafjallajokull eruption caused the planet's biggest airspace shutdown since World War II, lasting almost a month, owing to fears that the volcanic ash could affect aircraft engines.

Isavia spokeswoman Hjordis Gudmundsdottir said the fact that winds were blowing the ash to the north was far better than the eruption of Eyjafjallajokull, when a massive cloud of ash was blown to the south and southeast over mainland Europe.

Geophysicists at Iceland's Meteorological Office told Agence France-Presse that they expected the Grimsvoetn eruption to have far less impact on international flights than last year's blast.

"I don't expect this will have the same effect as Eyjafjallajokull volcano because the ash is not as fine," Gunnar Gudmundsson said. "I don't think this will have much of an effect on international flights, or that it will shut down airports abroad."

However, Einar Kjartansson, another geophysicist at the Icelandic Meteorological Office, insisted "it's much too early to say."

The BBC quoted Simon Calder, travel editor for the Independent, as saying "the eruption has been pretty fierce," with ash reportedly covering nearby villages and farms and, by Sunday morning, reaching the capital, Reykjavik, about 90 miles away.