REYKJAVIK, Iceland – Two earthquakes measuring over 5 in magnitude — the biggest yet — have shaken Iceland's Bardarbunga volcano after the country issued an aviation red alert warning that an ash-emitting eruption may be imminent.
Iceland's Meteorological Office recorded earthquakes of 5.3 and 5.1 in the early hours of Sunday.
The volcano, underneath Iceland's vast Vatnajokull glacier, has been rattled by thousands of small earthquakes over the past week.
On Saturday scientists reported a small eruption under the ice, but it was not visible on the surface.
Authorities have declared a no-fly zone of 100 nautical miles by 140 nautical miles (185 kilometers by 260 kilometers) around the epicenter as a precaution.
A 2010 eruption of Iceland's Eyjafjallajokul volcano caused a week of international aviation chaos, with more than 100,000 flights cancelled.