The mayor of nearby Lipari, Marco Giogianni, said necessary precautions had been taken, following a meeting with experts from the National Institute of Geophysics and Vulcanology (INGV) and Italy’s civil protection agency.

“The values are outside the norm in the top part only in the Vulcano crater,” Giogianni said in a live broadcast on Facebook.

“We live with a volcano and we know what that means ... I can’t stress enough that this is just a precaution.

“We will be monitoring the volcano’s activity to ensure everyone’s safety and peace of mind.”

Giogianni added that an order had been issued to prevent people from climbing to the top of the crater at around 500 metres, a 40-minute walk.

The measures will remain in place until further notice.

Marco Pistolesi, a vulcanology professor at the University of Pisa, also tweeted about the change in the alert level, referring to “increased degassing, temperatures, seismicity and deformation”.

“For those who know the island, this has never been observed before,” he wrote.

Located at the southernmost end of the seven Aeolian Islands, Vulcano contains several volcanic calderas, including one of the four active volcanoes in Italy that are not submarine.

The last eruption on Vulcano was over 130 years ago and took place from August 2, 1888, to March 22, 1890.

It has been still since then, but this “sleep” is sometimes disturbed by seismic activity crises and increases in steaming volcanic gas emissions from vents, or fumaroles.

The island’s some 1000 residents are always at risk due to gas-rich, high-temperature fumaroles, but with increased activity, there is a danger that the fumaroles could intensify and extend over larger areas.