- Written by Katherine Armstrong
- BBC News
A state of emergency has been declared in southern Iceland due to another volcanic eruption on the Reykjanes Peninsula, the fourth since December.
Among the people asked to leave the area are residents of the small town of Grindavik, which has been badly damaged by the ongoing confrontations.
The nearby Blue Lagoon, one of Iceland's most popular tourist attractions, was also evacuated.
Iceland's airspace remains open. Giant lava spill billowing smoke.
According to the country's Civil Defense Service, the eruption began after 20:00 local time (20:00 GMT) on Saturday between Hagafell and Stora Skogfell – north of Grindavik.
This is a similar location to the eruption that began on December 8.
Footage of the explosion showed clouds of smoke and glowing magma bleeding and boiling from holes in the ground.
Keflavik International Airport and other regional airports were not affected by the explosion.
Geophysicist Magnus Tommy Gudmundsson, who was among those who flew over the affected areas by helicopter, told local media that Saturday's eruption was the strongest yet.
Two tongues of lava were moving west and south. Local media reported that the lava emanating from the latter reached the eastern defensive walls of Grindavik.
It is also possible for lava to flow into the sea, but this may not happen if volcanic activity declines, Gudmundsson said.
Einar Besse Gestsson, a natural disaster expert at the Norwegian Meteorological Agency, told Iceland's public broadcaster RUV that dangerous gases and small explosions could occur if lava comes into contact with seawater.
Meanwhile, lava moving west is said to have reached the Grindavikurveg road to Grindavik – heading in the direction of the Blue Lagoon and the Svartsengi geothermal power plant, which supplies hot water to most of the Reykjanes Peninsula.
Ricky Pedersen, head of the Reykjavik-based Northern Volcanoes Centre, told Reuters that several protective dams had been built around them.
There are fears that the fiber optic cables on the road may be damaged, which could lead to interruption of telephone and Internet services.
The Blue Lagoon is closed until further notice as a precaution. Pedersen said there were between 500 and 600 people in the area when the eruption occurred on Saturday.
Between five and ten houses were also disinfected in Grindavik.
The town's roughly 4,000 residents were not allowed to return to their homes until about a month ago after a January eruption spread lava into the town, destroying three homes.
Most of them have chosen not to return.
Iceland has 33 active volcanic systems and is located above what is known as the Mid-Atlantic Ridge, the boundary between two of the largest tectonic plates on the planet.
The last time the Reykjanes Peninsula experienced a period of volcanic activity was 800 years ago, and eruptions have continued for decades.
This is now the seventh eruption since 2021, and scientists believe the region is entering a new volcanic era that may last decades or even centuries.