Iceland's Meteorological Institute has raised the alert warning for the country's largest volcano.
The institute raised the warning code Friday to red, the highest level, after a small eruption of the Bardarbunga volcano overnight.
Icelandic aviation officials have also closed down the airspace around the volcano.
However, the civil protection office said in a statement that no volcanic ash has been detected.
Ash from the eruption of Iceland's Eyjafjallajokull volcano in 2010 shut down much of Europe's airspace for six days. The eruption, a little over 100 kilometers from the capital, Reykjavik, affected more than 10 million air travelers and cost $1.7 billion.
Last week Icelandic officials raised the risk level to the aviation industry for an eruption to orange, which is the fourth level of a five-grade scale. That alert was lifted the next day.
