Watch: Skiers glide down slopes as Mount Etna erupts

Skiers took advantage of the Christmas holiday season by ski mountaineering on the slopes of Mount Etna, while Italy's most active volcano continued to erupt unabated.

Italy's Department of Civil Protection raised the alert level for Mount Etna from green to yellow yesterday, due to the possible rapid escalation of activity.

Nevertheless, people were not going to miss out on the opportunity to see the volcanic ash clouds up close or enjoy a day of ski mountaineering in pleasant weather.

"It's very impressive to climb at this time, with the contrast between the eruption, the snow and the sea just below," said volcanological guide Giuseppe Curcio, describing it as an 'unique experience'.

Despite the alert, flights were operating normally at Catania Fontanarossa Airport, authorities said, adding that no disruption was expected unless ash fall increased.

Rising more than 3,300 metres above sea level, Etna dominates eastern Sicily and is monitored around the clock.

Its frequent eruptions are a reminder of the powerful forces beneath one of Europe's most closely watched volcanoes.