A volcano in south-western Iceland has erupted for the sixth time since December, spewing red lava through a new fissure on the Reykjanes Peninsula.

The eruption began shortly after 9pm on Thursday after a series of strong earthquakes and within an hour a 2.4-mile fissure had been cut through the Sundhnukur crater.

Authorities said the effects remain localised with road closures and do not threaten the population.

Halldor Bjornsson, head of weather and climate at the Norwegian Meteorological Agency, told Icelandic news portal Visir, that unlike previous eruptions, the lava flow is not heading for the town of Grindavik which was largely evacuated in December when the volcano came to life after being dormant for 800 years.

Magnus Tuma Gudmundsson, a geophysicist who flew over the eruption centre, told the website: “If this continues like this, Grindavík is not in danger because of this.

“Of course, we don’t know what will happen in the near future, but it is likely that this has reached its peak and then it will start to subside like the other eruptions.”

As news of the eruption spread, hundreds of onlookers drove to nearby vantage points for a view of the natural phenomenon which has become a key tourism attraction.

“We just thought that it was the northern lights,” said Mahnoor Ali, visiting from Maryland in the US. “It’s like the coolest thing I’ve seen in my whole life, honestly.”

For people living and working on the peninsula, the regular eruptions and ensuing evacuation orders will be met with frustration.

The repeated eruptions close to Grindavík, a town of 3,800 people about 30 miles south west of the capital Reykjavik, have damaged infrastructure and property and forced many residents to relocate to guarantee their safety.

The few who had returned were forced out again on Thursday night as strong winds blew toxic gas over the town.

The nearby Blue Lagoon geothermal spa — one of Iceland’s biggest tourist attractions — was also evacuated with social media videos showing sirens blasting around dusk.

Iceland, which sits above a volcanic hot spot in the North Atlantic, averages one eruption every four to five years. The most disruptive in recent times was the 2010 eruption of the Eyjafjallajokull volcano, which spewed clouds of ash into the atmosphere and disrupted transatlantic air travel for months.

The latest eruption is not expected to affect air travel.