A number of people are feared to have been killed after a mudslide triggered by heavy rains swept away homes on the island of Ischia, near Naples.
The torrent of mud and debris dislodged trees, engulfed buildings and dragged cars into the sea as it reached the coast early on Saturday.
The body of a woman was reported to have been found under the mud, and several other people are still missing.
Dozens of homes are cut off, with bad weather hampering rescuers.
Resident Lisa Mocciaro told Ansa news agency: "We started hearing loud thunder at about 03:00 (02:00 GMT), then the first landslide came down, followed by a second one around 05:00. It was horrifying."
Interior Minister Matteo Piantedosi told reporters the situation was "very complicated" and that the people missing were believed to be trapped under the mud. Up to 155mm (6.1in) of rain fell over the course of six hours.
Heavy rains have been battering Campania, the region surrounding Naples and Ischia, for several days. A weather warning for rainfall and strong winds is in place until Sunday.
On Thursday, two people were killed due to bad weather in the region. An Argentine tourist drowned after being swept into the sea during a coastal storm, while a man was struck by lightning on a beach.
Local authorities are urging residents to stay home to avoid hindering emergency services.
Earlier, Infrastructure Minister Matteo Salvini said eight people had died in the landslide, adding: "From north to south, this country needs to be protected because it is the most beautiful country in the world."
But the interior minister later said that no deaths had yet been confirmed.
Like nearby Capri, Ischia, in the Tyrrhenian Sea, is a popular holiday destination for tourists and Italians alike. Ischia featured in the popular book series Neapolitan Novels by Elena Ferrante and was the backdrop to the 1999 film The Talented Mr Ripley.