A volcano in the southwestern portion of Iceland erupted on Monday after weeks of increased and intense seismic activity, according to the Icelandic Meteorological Office.

In a post on X, the Icelandic Met Office said the eruption started at about 10:17 p.m. local time, after an "earthquake swarm" that began an hour and 15 minutes prior.

The volcano is located about 3 km north of the fishing town of Grindavik, which has a population of less than 4,000 people.

Reuters reported that authorities evacuated the inhabitants of Grindavik and closed the nearby Blue Lagoon geothermal spa out of fear of a significant outbreak on the Reykjanes peninsula.

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The Met Office said a Coast Guard helicopter would be taking off to confirm the exact location and size of the eruption, adding that more information would be provided as soon as it becomes available.

An image posted to the agency’s website showed lava spewing out of cracks in the ground.

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Last month, a top emergency management official in Iceland revealed to Fox News on Monday that authorities there could get as little as "30 minutes notice" before a potential volcanic eruption in the southwestern part of the country. 

Vídir Reynisson, the head of the Civil Protection and Emergency Management agency, made the comment as the Icelandic Meteorological Office continued to report hundreds of small earthquakes surrounding the town of Grindavik, which could remain evacuated for months. 

ICELAND TOWN MAY BE EVACUATED FOR MONTHS AS VOLCANIC RUMBLING CONTINUES 

At the time, the office said there had been over 700 earthquakes detected in the region of magma intrusion, the biggest of which was a 2.7-magnitude tremor in the mountainous area of Hagafell, which is just north of Grindavik.

Authorities are warning residents of Grindavik that it may be months before they are able to return to their homes.

Grindavik, which was evacuated by the Icelandic government last week after seismic activity and air content analysis pointed to possible eruptions, has been shut down to traffic for the foreseeable future. 

Fox News’ Bryan Llenas, Timothy H.J. Nerozzi and Greg Norman, as well as Reuters contributed to this report.