Flash floods have inundated the Italian port city of Genoa after two rivers burst their banks and sent a torrent of water and mud down some streets.

One person was confirmed dead in the overnight storm, while residents were left without electricity, schools were closed and a train reportedly derailed due to the conditions.

News reports said police divers recovered a body near where the Bisagno river overflowed. The water dumped more than a metre of grey mud in parts of the city and surrounding areas and sent parked cars tumbling into one another.

The Italian Red Cross said two rivers had overflowed and some neighbourhoods were cut off from rescuers. The Italian civil protection department warned more rain was on the way.