LONDON -- Icelandic police say seismic activity near the Hekla volcano has prompted them to declare an "uncertainty phase" -- the lowest level of civil warning.
Monitoring of the area in southern Iceland has been increased. Police advise people not to hike in the area, though it is not forbidden.
Vidir Reynisson, the department manager for civil protection, said Tuesday that a swarm of earthquakes prompted the warning but are not necessarily a sign of pending eruption. Scientists worry that Hekla is overdue for an eruption; in recent decades it has erupted roughly every 10 years, most recently in 2000.
Concern about seismic activity in the north Atlantic nation has grown since April 2010, when ash from the Eyjafjallajokul volcano grounded flights across Europe for days, disrupting travel for 10 million people.