WATCH Violent Storms Spawn Tennis-Ball-Size Hailstones in Rome

Severe hailstorms ripped through the Italian capital of Rome on Sunday night, causing massive floods and disrupting city traffic.

The downpours swamped a number of streets, trapping many drivers in their cars; they have also soaked subway stations, forcing the closure of at least six of them, mostly in eastern parts of the city. All stations had reopened by Monday morning, The Local reports.

Water reportedly rose to one meter in Palmiro Togliatti, a street on the outskirts of Rome. The hailstorms also brought tennis-ball-size hailstones.

The rainwater rushed into San Sebastiano Fuori le Mura, a 4th century basilica, rising up to 50 cm above the floor.

According to Mayor of Rome Virginia Raggi, local police, firefighters, Civil Protection emergency forces, and volunteers have been deployed to tackle the extreme weather conditions.

Authorities have also issued orange alert (the second-highest level) for the southern regions of Molise and Calabria as well as parts of Basilicata and Puglia.