The roof of a construction machinery dealer lies across the building during a storm in Paderborn, Germany. [Source: NZ Herald]

A tornado swept through the western German city of Paderborn, injuring at least 30 people as it blew away roofs, toppled trees and sent debris flying for miles, authorities said.

Meteorologists had warned that heavy rainfall and hail were expected in western and central Germany, with storms producing wind gusts up to 130km/h. Storms had already disrupted traffic, uprooted trees that toppled onto rail tracks and roads and flooded hundreds of basements in western Germany.

Paderborn police said 43 people were injured in the storm that hit the city. Thirty were being treated in hospitals and 10 of those were seriously injured. One woman was in a life-threatening condition, police said.

They urged people to remain in their houses so as not to hamper rescue efforts or endanger themselves.

A damaged car is seen after a storm in Paderborn, Germany. 

Heavy storm damage was also reported in the nearby town of Lippstadt. A church steeple was toppled and German news agency dpa reported that more than 100 people were temporarily trapped in an open-air pool after fallen trees blocked the exit.

The regional fire service said all available rescuers were being deployed to the area.

Authorities in Bavaria said 14 people were injured on Friday when the wooden hut they were trying to shelter in collapsed during a storm at Lake Brombach, south of Nuremberg. Among the injured were several children and a 37-year-old woman, who was airlifted to a hospital with serious injuries.

Police said two French citizens died after their motorised paraglider was caught by a strong gust shortly after taking off on Thursday from an airfield in Ballenstedt, 175 kilometres southwest of Berlin. Police in Saxony-Anhalt state said the pair, both 59, were urged to land because of a forecast for an abrupt change in the weather.

Shortly after the warning, “they appear to have been hit by a gust of wind that caused the paraglider to collapse, and the air vehicle crashed onto a field from a height of about 40 metres”, police said.

Schools in the western city of Cologne closed before midday on Friday to give students time to make it home safely before the storms hit.

Further south in Ahrweiler county, all schools remained closed on Friday. More than 130 people were killed in the region last summer when it was hit by a flash flood in July.