Icelandic officials have declared an "uncertainty phase" because of seismic activity in Mount Hekla, one of Iceland's most active volcanoes.

There are no observable signs that an eruption of Mt. Hekla is imminent, according to RUV, the Icelandic National Broadcasting Service.

Unusual activity in Mt. Hekla prompted Icelandic officials to raise the International Civil Aviation Organization color code from green to yellow concerning air traffic, which means the volcano is experiencing signs of elevated unrest above known background levels.

Since March 10, "at least seven micro-earthquakes, ranging in size from magnitude 0.4 to 1, have been detected over a small area ~4.5 km to the north-east of the volcano's summit," the RUV report stated.

The earthquakes, at more than seven miles below the surface, are relatively deep, prompting Wired.com science writer Erik Klemetti so say the quakes "don't entirely suggest that new magma is intruding as they appear to reflect brittle fracture of rock rather than dilation due to magma. Coupled with a lack of any signs of ground deformation at Hekla, there are no signs that an eruption is imminent.

The uncertainty phase is part of the public safety process in Iceland and is used as a means to so secure formal communications between response teams. People have been advised not to hike on Mt. Hekla.

Mt. Hekla's most recent eruption was on Feb. 26, 2000. The volcano has a long and fiery history, with its first recorded eruption dating back to 1104. There have been as many as 30 considerable eruptions since then, some lasting just days and others much longer, such as the more-than-year-long eruption that began March 29, 1947 and continued until April 21, 1948.

A live feed of the volcano can be seen here.