Reykjavik’s nearby Keflavik International Airport remained open, albeit with numerous delays listed for both arrivals and departures.
Images and live streams of the eruption showed molten rock spewing spectacularly from fissures in the ground, their bright-yellow and orange colors set in sharp contrast against the dark night sky.
The crack in the earth’s surface was around 3.5 km long and had grown rapidly, the Met Office added.
Some 100 to 200 cubic meters (3,530 to 7,060 cubic feet) of lava emerged per second, several times more than in previous eruptions in the area, the Met Office said.
Local police said they had raised their alert level as a result of the eruption and the country's civil defence warned the public not to approach the area while emergency personnel assessed the situation.
