REYKJAVIK, March 31 (Reuters) - A volcano blasting steam and ash into the atmosphere in the south of Iceland formed new craters spewing lava on Wednesday, Icelandic radio said.
The volcano under the Eyjafjallajokull glacier began erupting 10 days ago, forcing hundreds of people to leave the area and leading authorities to divert flights.
A new fissure about 300 metres long opened up on Wednesday, state radio said. Geologists believe this could mean activity is moving further north, towards the nature reserve of Thorsmork, a popular tourist site.
Vidir Gardarsson of the Civil Defence in Reykjavik told the newspaper Morgonbladid the fissure was still expanding.
"We want to move people away from the area while we figure out what is going on," he said. "This is a security measure while this evolves."
Police estimate that about 25,000 people have visited the site in recent days.
Iceland lies on a volcanic hotspot in the Mid-Atlantic Ridge and is prone to eruptions, although most occur in sparsely populated areas and pose little danger to life or property. The last eruption took place in 2004.
Scientists had been monitoring the Eyjafjallajokull glacier, dormant since 1821, for signs of seismic activity but said there was little warning before the latest activity. (Editing by Andrew Dobbie)