ITALY (TNND) — Europe's largest and most active volcano, Italy's Mount Etna, erupted over the weekend with a massive cloud of ash and hot lava, forcing tourists to run for safety.

The National Institute of Geophysics and Volcanology, INGV Vulcani, said a pyroclastic flow, which is a combination of ash, rock and gas, "probably produced by the collapse of material from the northern side of the Southeast Crater."

Infrared images shared by the group showed lava flowing down the mountain. "Explosive activity from the Southeast Crater has become a lava fountain," INGV Vulcani added.

No injuries were reported.

The U.S. Geological Survey (USGS) describes the mountain as an active stratovolcano known for its frequent and persistent eruptions.

Videos shared on social media showed tourists running along a path on the side of the volcano as smoke billowed in the distance.

Just over a year ago, Mount Etna erupted and was seen blowing spectacular "smoke rings" into the sky.

Giuseppe Barbagallo, a member of the South Etna Alpine Guides Group, told Reuters that Mount Etna was experiencing a rare phenomenon, known as "volcanic vortex rings," which is generated by the combination of rapid gas release.