“Something like this is absolutely impossible to predict,” meteorologist Sebastian Wache told dpa, adding that the tornado had originated on the outskirts of Kiel.

According to the fire department, four people were seriously injured, while three others suffered moderate injuries. Some of those injured were hit in the head by flying objects.

Roofs were torn from houses and tiles came loose, the fire brigade said. A series of videos of the incident were circulating online.

The chairman of the First Kiel Rowing Club, Bernd Klose, referred to the situation as “sad,” saying that a tree had fallen and rubbish bins had been overturned.

“There were a lot of [objects] flying around,” said an employee of a nearby restaurant. “It caused everyone emotional distress.”