The Icelandic Meteorological Office said that the shaking felt in communities near Eyjafjallajökull glacier was due to magma flowing “at full speed” into the volcano.
Eyjafjallajökull last erupted in 1821-1823, and previously in 1612.
In 1994 and 1999 a series of tremors was detected in the area — believed to have been caused by magma intrusion deep inside the volcano.
The Civil Protection Department was maintaining an alert for the mountain due to the unrest.
Photo: Iceland Tourism