THEY occur at a rate of nearly one a night, without warning or fanfare. By the time the police arrive, all that remains are smoking wrecks. Even the identifying badges  Porsche, BMW, Mercedes, VW  are often obliterated by fire.

In a city haunted more by its extreme right-wing past, Berlin is in the throes of a renaissance of extremist, left-wing political activism. And torching cars, particularly expensive ones, has become the crime de rigueur.

During the past six months, more than 170 cars have been destroyed by fire in Berlin and police confirm conservatively that 93 were politically motivated attacks.

A mysterious, single page website, brennende-autos.de (Burning Cars of Berlin), shows the number of cars set alight and where the crimes occurred, revealing clusters in richer areas, or in suburbs where gentrification and redevelopment are changing the demographic of local neighbourhoods.

Demonstrations and protests in Berlin have also become more violent. During the past seven months traditional street marches or political celebrations such as May Day  when 21 police were hurt and 102 arrests made  have degenerated into ugly confrontations between left-wing activists and an increasingly frustrated police force.