A volcano in southwest Iceland sent lava cascading towards the fishing town of Grindavik early on Sunday, after hundreds of earthquakes shook the region and forced the evacuation of residents overnight. The incident occurred less than a month after another powerful eruption in the region.

Saturday’s seismic activity, often a calling card for an imminent eruption, prompted officials to evacuate the town, about 32 miles southwest of the capital Reykjavik, hours ahead of the volcanic event – which occurred at about 8am GMT.

The latest eruption, on the Reykjanes Peninsula where a string of volcanoes are located, follows a fissure last month that erupted and emitted a river of lava. The molten rock flowed away from Grindavik on that occasion. Residents were permitted to return to the town on December 22, about six weeks after they had been initially evacuated from their homes following weeks of earthquakes.

In the weeks following December’s event, defensive walls were constructed around sections of the volcano’s perimeter in the hope of diverting lava flows away from the Grindavik community of about 3,800 people. However, the barriers – made from earth and rock – appear to have been breached by magma, officials said.