London: The Icelandic Met Office raised its aviation warning level near the Bardarbunga volcano to red after an eruption began, BBC reported on Friday.
Scientists said a fissure eruption one-km-long started in a lava field near Vatnajokull glacier.
Civil protection officials said Icelandic Air Traffic Control has closed the airspace above the eruption site up to a height of 5,000 ft.
The volcano has been hit by several recent tremors.
The fissure eruption took place between Dyngjujokull Glacier and Askja caldera, a statement by the department of civil protection said.
"Scientists who have been at work close to the eruption monitor the event from a safe distance," the statement said.
"The Icelandic Met Office has raised the aviation colour code over the eruption site to red."
It added that no volcanic ash had so far been detected but a coast guard aircraft was due to take off later to survey the site.
On Thursday, scientists said they were examining several "cauldrons" found near Bardarbunga volcano that could potentially be a sign of an eruption.
The cauldrons are depressions in the volcano's surface, each between 49 ft deep and 1 km wide, were seen Wednesday.
Bardarbunga is part of a large volcano system hidden beneath the Vatnajokull ice cap in Iceland.
Iceland's Eyjafjallajokull volcano erupted in 2010, producing ash that disrupted air travel across Europe.