An Icelandic volcano erupted on the Reykjanes peninsula

A volcano erupted on the Reykjanes peninsula in southwest Iceland after weeks of seismic activity.

Around 4,000 people were earlier evacuated from the fishing town of Grindavik and the nearby Blue Lagoon geothermal spa was closed.

The eruption began north of the city at 22:17 local time (22:17 GMT), the Icelandic Meteorological Office said.

One expert said it would not bring the same level of disruption as the 2010 shutdown of European air travel.

Earthquake activity has been increasing in the area around the capital Reykjavík since late October.

A volcanic eruption occurred about 4 km (2.5 miles) northeast of Grindavik and seismic activity was moving toward the town, the meteorological office said.

Images and videos posted on social media showed lava erupting from the volcano an hour after the earthquake swarm or seismic events were detected.

The eruption can be seen from Reykjavík, about 42 km northeast of Grindavik.

A witness there told the BBC that half of the sky in the direction of the city was “lit red” from the explosion and smoke could be seen billowing into the air.

Police have warned people to stay away from the area.

The length of the eruption is about 3.5 kilometers and the lava is flowing at a speed of about 100 to 200 cubic meters per second, according to the Meteorological Department.

It added that this is several times more than previous eruptions on the Reykjanes Peninsula in recent years.

A senior police official from the Civil Defense told national broadcaster RUV that the explosion happened quickly and appeared to be a “very large event”.

Vidir Reinison said lava appeared to be flowing in all directions from a large crack in the volcano.

Iceland’s foreign minister, Bjarni Benediktsson X, said earlier on Twitter that there were “no disruptions to flights to and from Iceland, and international flight corridors will remain open.”

“The Jets [of lava] “It’s very high, so it looks like a powerful explosion at the beginning,” he said.

Halgrimur Indíriosson, a reporter for the state-owned Icelandic National Broadcasting Service (RUV), said the eruption could be seen from Reykjavík, 50km away, and described the scene as “very spectacular”.

Iceland has been under threat of volcanic eruption for weeks, and last month authorities ordered people to leave the town of Grindavik as a precaution.

No injuries were reported.

Volcanologist Dr Evgenia Ilinskaya told the BBC that there would not be the same level of disruption as in 2010, as these volcanoes in south-west Iceland are “physically incapable of producing homogeneous ash clouds”.

The Eyjafjallajokul volcano in southern Iceland is about 140km (87 mi) from the volcano on the Reykjavik peninsula.

Speaking from Iceland, Dr Ilinskaya, associate professor of volcanology at the University of Leeds, said local people were “waiting in fear” for the volcano to erupt.

“There was a lot of uncertainty. It was a difficult time for local people,” he said.

He added that authorities were preparing for lava flows that could destroy homes and infrastructure, including the popular tourist destination Blue Lagoon.

“At the moment it doesn’t appear to be a threat, but that remains to be seen,” he said.

Iceland’s Prime Minister Katrin Jakobsdóttir said the recently built defenses would have a positive effect.

He said his thoughts were with the local community and hoped for the best despite the “significant event”.

President Kutni Johansson said saving lives was the top priority, but all efforts would be made to protect structures.