A volcano erupted north of the southwestern Icelandic town of Grindavik early Sunday, near the site of a previous eruption in December, the Icelandic Meteorological Office (IMO) said.

Seismic activity had intensified overnight and residents of Grindavik were evacuated around 3 am (0300 GMT), Icelandic public broadcaster RUV reported.

"A crack has opened up on both sides of the dikes that have begun to be built north of Grindavik," the met office wrote.

Live images showed jets of glowing orange lava spewing up against the dark winter sky.

This is Iceland's fifth volcanic eruption in two years, the previous one occurring on December 18 in the same region southwest of the capital Reykjavik.

Grindavik, a small fishing village of around 4,000 people, was evacuated as a precaution on November 11.

Since then, residents have been allowed to return for brief periods, before an evacuation was again ordered overnight.

Iceland is home to 33 active volcano systems, the highest number in Europe.

Situated in the North Atlantic, Iceland straddles the Mid-Atlantic Ridge, a crack in the ocean floor separating the Eurasian and North American tectonic plates.