Berlin's fire brigade declared a state of emergency and said it had received 50 emergency calls on Thursday as storm Xavier made its destructive progress across the north of the country. Hamburg's fire brigade also received hundreds of calls and issued a warning, telling residents to stay indoors as the storm passed.
Category 3 storm warnings, on a scale that goes up to 4, were issued for much of northern and eastern Germany.
"Warning for Hamburg. Do not go outside at the current time, stay in protected areas," the fire brigade said on Twitter.
One woman was killed in Hamburg after a tree fell onto her car. A man died in his lorry in the eastern German state of Mecklenburg-Western Pomerania after a tree struck his vehicle, police said.
Police in the state of Brandenburg near Berlin later said that four people had died in their vehicles.
Bus services began to run again in Berlin on Thursday evening but a spokesman for BVG Berlin transport said the service may not be fully restored until after Friday morning and checks on the network had been made.
Hundreds of people were stranded as their trains were canceled in the capital. Deutsche Bahn canceled long-distance trains to and from Berlin as well as services in Lower Saxony, Schleswig Holstein and Bremen and commuter trains in Hamburg.
Bremen and Hanover airports canceled some international flights.
Passengers arriving in Berlin remained on board their aircraft as the storm swept over Tegel and Schoenefeld airports and authorities temporarily suspended operations.
The German Weather Service (DWD) said the storm had reached hurricane-strength wind speeds of between 105 and 115 kilometers (65 and 71 miles) per hour.
The storm uprooted trees and tore roofs off buildings as it crossed over three states.
Berlin's two zoos closed and reported on Twitter that "elephants, zebras and giraffes ... are retreating to the safety of their enclosures."
A large, heavy crane in the North Sea port city of Wilhelmshaven fell into the Jade River during the storm.
The storm is expected to move eastwards into Poland during the course of the night.
Increasing insurance claims
Last year, German insurers paid out €940 million ($1.1 billion) to cover claims for storm damage. The figure was 10 times higher than the previous year when it was about €100 million. The cause of the extensive damage was a large number of storms over a short period of time, according to Wolfgang Weiler, head of the German Insurance Association (GDV). For this year, summer storm damage has already cost the insurance industry €600 million.
jm/msh (dpa, AFP)