A small volcano eruption that forced more than 600 people to flee their homes in Iceland over the weekend could conceivably set off a larger volcano, experts warned Monday.

"Historically, we know of three eruptions in (the large volcano) Katla linked to eruptions in Eyjafjallajokull," Magnus Tumi Gudmundsson, a professor of geophysics and civil protection advisor, told AFP, adding however that there so far was no indication of volcanic activity at Katla.

A volcanic eruption near the Eyjafjallajokull glacier in southern Iceland forced hundreds to flee their homes early Sunday, but no casualties were reported.

It was the first volcanic eruption in Iceland since 2004, and the first in the vicinity of the Eyjafjallajokull glacier since 1823.

Icelandic authorities warned Monday of increased disturbance in the area.

"Police have increased surveillance in the whole area around the Eyjafjallajokull and Myrdalsjokull glaciers because of increased disturbance this morning in the volcanic eruption," the police and civil protection department said in a statement.

Police also warned there could still be danger in travelling or driving in the vicinity of the volcanic area and closed some of the area's roads.

Public broadcaster RUV reported small earthquakes in the region of the volcanic eruption were measured early Monday, and said the 800 metre (yard) fissure caused by the eruption was getting larger.

Gudmundsson however said that while the lavafield from the fissure had grown, "the fissure itself has not grown or enlarged."

He also said the threat of the fissure heading towards the Myrdalsjokull glacier, which sits on top of Katla had diminished.

Katla, which is considered one of the most dangerous volcanos in Iceland, last erupted in 1918.

"An evacuation plan exists if Katla goes off but now we are just taking it day by day and refocussing on the Eyjafjallajokull evacuation plan and what is going on there," local police chief Kjartan Thorkelsson told AFP.

Historically, Katla has erupted within a year of an eruption at Eyjafjallajokull, but Gudmundsson tried Monday to downplay the danger.

"Katla is extremely well-monitored by GPS earthquake monitoring devices and there is nothing to indicate that something is going on in Katla," he insisted.