Iceland's most active volcano erupted Saturday, with a white plume shooting 18,000 feet into the air, scientists said.

The eruption was followed by around 50 small earthquakes, the largest of which measured 3.7 on the Richter Scale, according to Iceland's meteorological office.

Iceland has closed its main international airport as a volcanic eruption sends a plume of ash, smoke and steam 12 miles (20 kilometers) into the air.

Airport operator ISAVIA said Keflavik airport was closed at 0830 GMT.

Spokeswoman Hjordis Gudmundsdottir said the ash plume was covering Iceland, but was not heading toward Europe.

She said the ash was blowing west toward Greenland instead.

The Grimsvotn volcano, which lies under the uninhabited Vatnajokull glacier, began erupting Saturday for the first time since 2004.

In April 2010, ash from the Eyjafjallajokull volcano was blown toward Europe. Officials closed the continent's air space for five days, fearing the ash could harm jet engines. Some 10 million travelers were stranded.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

REYKJAVIK, Iceland (AP) — Scientists say a plume of ash, smoke and steam from a volcano in Iceland has risen 12 miles (20 kilometers) into the air, but there is no sign yet that it will disrupt international airline traffic.

The Grimsvotn volcano began erupting Saturday for the first time since 2004.

Police closed a main road near the volcano Sunday as heavy ash fell in the sparsely populated area.

Air officials ordered a no-fly zone of 120 nautical miles (220 kilometers) in all directions around the volcano, which lies under the uninhabited Vatnajokull glacier.

In April 2010, ash from the Eyjafjallajokull volcano was blown toward Europe. Officials closed the continent's air space for five days, fearing the ash could harm jet engines. Some 10 million travelers were stranded.