Italy’s Mount Etna erupted Monday, sending a towering plume of ash, gas, and rock into the sky, but authorities said there was no immediate threat to nearby residents.

The eruption began around 11:24 a.m. local time (0924 GMT), with surveillance cameras capturing a pyroclastic flow from the northern flank of the volcano’s Southeast Crater, the National Institute of Geophysics and Volcanology (INGV) reported.

“A pyroclastic flow probably produced by a collapse of material from the northern flank of the Southeast Crater,” the agency said. The eruption later transitioned to a lava fountain, with the ash plume drifting southwest, INGV added.

A pyroclastic flow involves fast-moving clouds of hot gas, ash, and volcanic debris and can be extremely dangerous.

Sicilian regional president Renato Schifani said there was “no danger for the population,” noting the flow had not crossed into the Valley of the Lions, a popular tourist area.

Videos shared on social media appeared to show tourists retreating from the volcano, some stopping to take photos. AFP could not independently verify the footage.

“The partial collapse of the Southeast Crater, which generated an impressive eruptive cloud several kilometers high and a pyroclastic flow, is a phenomenon that we follow with extreme caution,” Schifani said.

Salvo Cocina, head of Sicily’s civil protection unit, urged tourists to stay away from the area “in consideration of the potential evolution of the phenomenon.”

A red aviation alert estimated the volcanic cloud’s height at 6.5 kilometers (more than four miles), though nearby Catania airport remained operational.