A tornado with winds of up to 180 kilometres an hour left six people injured and damaged buildings as it passed through the outskirts of the northern German port of Kiel, authorities said on Thursday.
"Something like this is absolutely impossible to predict," meteorologist Sebastian Wache told dpa.
"If the tornado had passed through the city centre, roof tiles could have flown around like bullets," Andreas Friedrich of the German Weather Service told dpa.
He described the tornado, which struck late on Wednesday, as relatively weak by tornado standards and estimated wind speeds at between 118 and 180 kilometres an hour.
According to the fire department, six people were injured, three of them seriously, while trying to haul a rowing boat out of the water. Several people fell in.
Roofs were torn from houses and tiles came loose, the fire brigade said. A series of videos of the incident were circulating online.
"There were a lot of (objects) flying around," said an employee of a nearby restaurant. "It caused everyone emotional distress."
Climate researcher Mojib Latif of the city's Geomar Helmholtz Centre for Ocean Research said tornadoes were impossible to predict, relatively rare and that this one could not be linked to global warming.
Nevertheless, Kiel had had a lucky escape, he said. "Tornadoes occur over a small range, but they can devastate entire streets if you're unlucky, and then people can die," Latif said.
A tornado that hit Kiel in May 1973 left one person dead and more than 100 injured.
