Icelandic authorities briefly raised the aviation warning code to red after a small eruption near Bárðarbunga volcano, but no volcanic ash has been detected by the radar system.

The fissure eruption on Friday – which took place in the Holuhraun lava field, three miles (5km) north of Dyngjujökull glacier – was not highly explosive and produced little of the fine ash that can affect aircraft engines.

The airspace is closed three nautical miles around the eruption area up to 1,524 metres (5,000ft) – meaning it does not affect commercial flights flying over Iceland. The aviation code for Bárðarbunga was originally raised to red but was lowered to orange since there was no significant ash production, the civil protection department said.

"If this eruption persists it could become a tourist attraction, as it will be relatively safe to approach, although the area is remote," said David Rothery, a professor of planetary geosciences at the Open University in Britain. "This event should not be seen as 'relieving the pressure' on Bárðarbunga, nor is it a clear precursor sign of an impending Bárðarbunga eruption."

A fissure eruption happens when a crack opens up above a magma intrusion. The one at Holuhraun is about 0.5 miles long and is not producing any significant ash.

So far the eruption shows no sign of being as disruptive as the one in 2010, when Iceland's Eyjafjallajökull volcano erupted and sparked a week of international aviation chaos. Thousands of flights were cancelled when officials closed Europe's air space for five days, fearing that volcanic ash could harm jet engines.

Since Thursday night, the national crisis coordination centre and local coordination centres have been activated and are operating on an emergency basis. All access to the area where the eruption is occurring is closed.