The volcano on Iceland’s Reykjanes Peninsula erupted for the fourth time since December on Saturday night, the country’s meteorological office said, spewing smoke and lava into the air in stark contrast to the dark night sky.

Live feeds from the area showed fountains of molten rock rising from fissures in the ground after authorities warned for weeks that an eruption was imminent in the area, south of Reykjavik.

“Warning: An eruption has started in Reykjanes,” Iceland’s Meteorological Office said on its website, while Reykjavik’s Keflavik Airport showed it remained open for both departures and arrivals. The site of the new eruption has been located between Hagafell and Stora-Skogfell, the same area as the previous one on February 8, the Met Office said.

The nearby fishing town of Grindavik, where some of the nearly 4,000 residents had returned after previous outbreaks, was being evacuated again, public broadcaster RUV reported. The eruption in January burned even several houses. Icelandic police said they had declared a state of emergency in the area and the Civil Defense authority sent a helicopter to study the extent of the eruption.

Volcanic eruptions on the Reykjanes Peninsula are so-called fissure eruptions, which do not usually cause large explosions or a significant dispersion of ash into the stratosphere. In 2010, ash clouds from the Eyafjallajokull volcano eruptions spread across much of Europe, causing the cancellation of some 100,000 flights and forcing hundreds of Icelanders to evacuate their homes. However, scientists fear they could continue for decades, and Icelandic authorities have begun building dams to divert fiery lava flows away from homes and critical infrastructure.

Iceland has more than 30 active volcanoes, making the island a main destination for volcano tourism, attracting thousands of curious people every year.