A volcano erupted in Iceland near the capital Reykjavik on Wednesday, the Icelandic Meteorological Office (IMO) said as live images on local media showed lava spewing out of a fissure in the ground.

The eruption was some 40km from Reykjavik, near the site of the Mount Fagradalsfjall volcano that erupted for six months in from March to September in 2021, mesmerising tourists and spectators who flocked to the scene.

"Eruption has started near Fagradalsfjall. Exact location has yet to be confirmed," the IMO, which monitors seismic activity, wrote on Twitter.

It later said the eruption started in the valley of "Meradalir, about 1.5km north of Stora Hrut".

While there was no ash plume, the IMO said it was "possible that pollution can be detected due to the gas release".

No airline flights were currently affected, Iceland's national airport authority said.

Mount Fagradalsfjall belongs to the Krysuvik volcanic system on the Reykjanes peninsula in southwestern Iceland.

Iceland has 32 volcanic systems currently considered active, the highest number in Europe. The country has had an eruption every five years on average.

The vast island near the Arctic Circle straddles the Mid-Atlantic Ridge, a crack on the ocean floor separating the Eurasian and North American tectonic plates.

The shifting of these plates is in part responsible for Iceland's intense volcanic activity. (AFP)