Barbarbunga volcano, located under the ice cap of Vatnajokull glacier, trembled overnight, according to the Icelandic Met Office.
Three earthquakes in excess of magnitude 3 registered between 3:52 am and 3:56 am.
They were all in the southern part of the caldera.
Altogether, ten tremors registered.
The largest earthquakes were of magnitude 4.0, 3.9 and 3.3. No tremors have followed, but the area is closely monitored.