LONDON -- A volcano erupted north of Grindavík, Iceland, just before 8 a.m. on Sunday, the Icelandic Met Office said.
A Coast Guard helicopter flew over the site, sending photos back that appeared to show lava flowing from "both sides of the defenses that have begun to be built north of Grindavík," the Met said in an update posted in Icelandic. The lava was about 450 meters from the town, officials said.
"Judging by the pictures, lava is now flowing towards Grindavík," the Met said.
The eruption followed an "intense" series of earthquakes that began around 3 a.m. near where a volcano erupted in December, the Met office said.
"At the time of publication, over 200 earthquakes have been measured in the area, and the seismicity has moved towards the town of Grindavík," weather officials said in a notice posted before the eruption.
The earthquakes were in theSundhnúksgígarcrater, an area north of the town. The largest measured was an about 3.5 magnitude quake just after 4 a.m., the Met said.
Preliminary data showed Sunday's eruption just southeast of Hagafell, a mountain on the Reykjanes peninsula, the Met said.
About 4,000 Grindavík residents were evacuated in November, as tens of thousands of earthquakes rumbled the region. Those tremors signalled a high likelihood of an eruption, Met officials said at the time.
Some residents had returned in recent weeks, as the government worked to build a kilometers-long berm in an attempt to protect the town from future eruptions.
That town was again ordered to evacuate on Saturday, officials said in a statement ahead of Sunday's eruption.
As the lava flowed toward the town, workers could be seen moving construction equipment out of its path.