The disaster occurred in the town of Brazzano di Cormons, in the province of Gorizia near Trieste, and was sparked by a massive downpour that caused widespread flooding and sent mud pouring through the streets.

Late Monday, a spokesman for the national fire service told AFP they had identified "the body of the missing woman."

Earlier, spokesman Luca Cari said they found the body of the first missing person under the rubble, without identifying the victim.

News reports have said they are a 32-year-old German resident and his 83-year-old female neighbour, whom he was checking on during the downpour when the mudslide hit.

The mayor of Brazzano di Cormons, Roberto Felcaro, said the pounding rains "brought our community to its knees".

About 260 millimetres of water (10 inches) fell in approximately eight hours, causing "serious damage and problems throughout our territory", he said in a video posted on social media.

"There is a massive presence of law enforcement, firefighters, and civil protection agencies working tirelessly."

Earlier Monday, rescue workers managed to pull one man to safety from under destroyed homes. He was sent to hospital with a broken leg, local news reported.

Some 300 people were evacuated from the roofs of their homes amid the flooding, said Vannia Gava, an official from the region of Friuli-Venezia Giulia.

Video images taken by helicopter showed much of the area submerged by water.

Weather alerts have been issued across northern Italy due to bad weather.