Here is the link (in Icelandic):
Gos að hefjast i Grímsvötnum - mbl.is
Grímsvötn are located under Vatnajökull glacier, and have seen 13 eruptions since 1902.
The article sais that definite signs of impending eruption were observed by the Icelandic Meteorology office around 18:00 UTC, and a meteorologist is quoted: "all signs point to an impending eruption in the area."