The eruption started at 9:26 pm (21:26 GMT) on Thursday, with live video images showing red lava spewing out of a new fissure on the Reykjanes Peninsula, the Icelandic Meteorological Office said.
The total length of the fissure was about 3.9 km (2.4 miles) and had extended by 1.5km (0.93 miles) in about 40 minutes, said the met office in a statement.
Iceland’s Ministry for Foreign Affairs said the eruption did not “present a threat to life” and that the nearby area had been evacuated. “The impact is limited to a localized area near the eruption site,” it posted on social media platform X.
Most of Grindavik’s 4,000 residents had evacuated in November, prior to an eruption in December, and while residents have since been allowed to return in between eruptions, only a few have opted to stay overnight, Al Jazeera reported.
The eruptions show the challenge faced by the island nation of nearly 400,000 people as scientists warn that the Reykjanes Peninsula could face repeated outbreaks for decades or even centuries.
Since 2021, there have been nine eruptions on the peninsula, six occurring since December, following the reactivation of geological systems that had been dormant for 800 years.
Iceland boasts more than 30 active volcanoes, making the north European island a prime destination for volcano tourism – a niche sector that attracts thrill seekers.