A volcano has erupted on the Reykjanes peninsula in southwest Iceland, after weeks of intense earthquakes. The explosion began north of the city at 10:17 p.m. local time, according to the Icelandic Met office.
About 4,000 people were previously evacuated from the fishing town of Grindavik and the Blue Lagoon geothermal spa was closed.
The region around the capital Reykjavik has experienced an increase in earthquake activity since late October.
Images and videos posted on social media showed lava erupting from the volcano, just an hour after several earthquakes and seismic events were detected.
The Meteorological Office said the explosion was located about 4km northeast of Grindavik and the seismic activity was moving towards the town and was many times greater than previous explosions on the Reykjanes peninsula in recent years.
The length of the fissure in the volcano is about 3.5 km, with lava flowing at a rate of about 100 to 200 cubic meters per second, he added.
President Gudni Johannesson said that protecting lives was the top priority, but that every effort would be made to protect structures as well.
In April 2010, the Eyjafjallajokull volcanic eruption caused the largest closure of European airspace since World War II as a result of a large ash cloud. Losses were estimated between 1.5 and 2.5 billion euros.
Scientists say a new eruption is likely to produce lava, but not ash clouds.
Grindavik, a fishing town of 3,400 inhabitants, is located on the Reykjanes peninsula, about 50 kilometers southwest of the country's capital, Reykjavik, and not far from Keflavik Airport, Iceland's only international airport.