Residents in the nearby fishing town of Grindavik and guests at a luxury geothermal spa resort are evacuated.
The Sundhnukur volcano has erupted near Iceland’s capital, Reykjavik, the 12th volcanic eruption in the North Atlantic island nation since 2021, the Icelandic Meteorological Office says.
The agency said in a statement on Wednesday morning that an eruptive fissure in southwestern Iceland is 700 to 1,000 metres (765 to 1,095 yards) long.
“Lava is mostly flowing to the southeast and is not approaching any infrastructure,” it added. “Based on GPS measurements and deformation signals, it is likely that this was a relatively small eruption.”
Live images showed flows of lava and smoke being belched into the sky.
People were evacuated from the Blue Lagoon, a luxury geothermal spa resort, and the nearby fishing town of Grindavik, according to the public broadcaster RUV, which quoted police.
Rather than flowing from a central crater, lava from fissure eruptions like Wednesday’s appears from long cracks in the Earth’s crust.
Iceland, which is often referred to as a land of ice and fire, has now recorded a dozen volcanic eruptions since geological systems on its Reykjanes Peninsula reactivated four years ago.
The Reykjanes eruptions have so far neither posed a threat to nearby Reykjavik nor have they caused air traffic disruptions, unlike the 2010 eruption of the Eyjafjallajokull volcano, which grounded planes across Northern Europe for almost a week.
Grindavik was home to almost 4,000 people before an evacuation order was issued in 2023. Now, it is mainly deserted because of the threat of lava flows and related earthquakes.
In early April, a volcanic eruption penetrated protective barriers close to Grindavik, and the emergency services evacuated its residents and those staying at the Blue Lagoon spa.
Experts have said eruptions on the peninsula could continue for decades.
Every year, Iceland, which has a population of nearly 400,000 people, attracts hundreds of thousands of visitors who come to explore its volcanic landscape.
In 2024, almost 2.3 million foreigners travelled to the island, according to its tourist board.