One man was killed and more than 30 people injured when a tornado and violent storms hit northern Germany, ripping tiles off roofs, downing trees and overturning cars, emergency services said Wednesday.

Worst hit was the town of Buetzow near the northern port of Rostock, where bricks lay scattered in the streets after flying debris had badly injured one person and hurt dozens of others late Tuesday.

Eyewitnesses spoke of a "tornado" that ripped through the town of 7,800 people, where the local hospital was also damaged and a sports hall was used as a temporary shelter for people forced to leave their homes.

A 26-year-old man was killed in the northern port city of Hamburg when parts of a roof toppled onto his car in the downtown harbourside area, also badly injuring his pregnant girlfriend who was seated next to him.

Trees crashed onto roads and rail lines in the states of North Rhine-Westphalia and Mecklenburg-Western Pomerania and disrupted public transport in Hamburg, where five container ships were also temporarily ripped from their moorings.

The thunder storms, with heavy rains and packing wind gusts that topped 100 kilometres (60 miles) per hour, came at the end of what had been the hottest and most humid day of the year so far, with temperatures up to 28 degrees Celsius (82 degrees Fahrenheit).