Four people died overnight in a landslide due to a wave of adverse weather that swept Italy from north to south at the weekend, local media reported Sunday.

A local entrepreneur and three workers -- all reportedly men aged in their 40s to 50s -- were submerged by a pile of earth and mud while working on a sewage pipe amid torrential rain on a private property near the city of Crotone in the southern Calabria region located in the tip of Italy's boot, according to RAI News 24 public broadcaster, which showed rescue personnel at the site of the incident where the four bodies were recovered at dawn.

In the Ionian Sea off Crotone, the Coast Guard deployed a helicopter as well as a boat to reach and tow to safety a sailboat with dozens of migrants on board, which had been at the mercy of high waves for hours within sight of the coast, said local news outfit Crotone News and Italian news agency ANSA, which showed footage and photos of the boat being battered by the waves and of the helicopter hovering near it.

Earlier this month, also in the Calabria region, a young mother and her two children -- one of them a toddler -- died after being trapped in their car by a flood due to torrential rains.

The national Civil Protection Agency has issued red and orange alerts -- meaning possible "loss of life" from landslides, floods, and infrastructural damage -- due to an Atlantic storm system that has brought torrential rains and hail, electrical storms, powerful winds and high seas to Italy from North to South over the weekend.

Civil Protection alerts run from green (not critical), yellow (moderately critical), orange (critical) and red (highly critical).

In the northwestern city of Genoa, a tornado tore through the city's busy port, uprooting trees and tearing roofs off buildings, ANSA reported.

In the northeastern city of Venice, authorities deviated a portion of the 33rd Venice Marathon due to flooding as RAI showed footage of the international competitors running through the water-logged streets of the city on the lagoon.

"Crisis unit assembled to take stock of adverse weather affecting most of Italy," the Civil Protection Agency tweeted on Sunday, adding it is "closely monitoring the situation in close contact with local authorities."