Storms lashing Sicily have killed at least 12 people after causing catastrophic floods, Italian authorities said Sunday.

Among the dead are nine members of two families who were spending a long weekend together in a country home near Palermo that was flooded by water from a rapidly swelling river.

Rushing water rapidly filled the villa in Casteldaccia in the province of Palermo, wiping out the families who were spending Saturday night there to celebrate the national holiday of All Saints' Day.

State broadcaster RaiNews24 said the sole survivor of the flooded home in Casteldaccia was stepping outside when the torrent of water and mud rushed in.

Giuseppe Giordano told reporters that when he opened the door, "there was a river of water, I was knocked down and grabbed hold of a tree. I was yelling, 'Help, help.'"

Italian news reports said the dead included a one-year-old, a three-year-old and a teenager.