Mount Etna, the tallest and most active volcano in Europe, erupted on Monday on the Italian island of Sicily. Dramatic video footage shared on social media showed tourists fleeing down the side of the mountain as a thick volcanic cloud intensified above them.

Mount Etna, whose stunning peak rises 11,014 feet tall and slopes toward the Ionian Sea, is a popular attraction for both hikers and tourists. Video footage obtained by CNN shows a tour group running downhill away from the explosion on June 2; Italian officials have confirmed that all hikers were evacuated safely.