“This is not terrorism, but we also shouldn’t downplay it,” said Dieter Wiefelspütz, a member of Parliament for the left-leaning Social Democrats. “When perpetrators believe that they will not be held accountable, that is dangerous for the constitutional state.”

In past years, the arson emerged in predictable patterns. There was an obvious emphasis on luxury sedans and SUVs, and fast-gentrifying neighborhoods like Friedrichshain, a former punk holdout, were hit particularly hard. But now, the attacks seem to have spread to every corner of the city and to include passenger cars of every sort.

On Kappenstrasse, in the neighborhood of Rudow, a nondescript Mitsubishi Carisma went up in flames on Tuesday morning, leaving the entire front end burned out, the engine blackened and one hubcap melted to the curb. Rudow is not hip like the central Mitte district. It is not the chic, well-heeled Charlottenburg, nor is it the gentrified post-Communist Prenzlauer Berg. It is a normal residential neighborhood, far from the city center at the end of a subway line.

“It was around 4:30 in the morning, and my husband was getting ready for work when he saw it,” said Anja Drah, who lives right where the car was set on fire. “I grabbed my daughter from her room. I was afraid the fire might spread to the house.”

Up to this point no one has been injured in the blazes. But underscoring the potential hazard to life and limb, just a few blocks away on Neuköllner Strasse the heat from another burning car cracked the ground floor windows of the closest building and left black scorch marks up to the second floor.

“The police can’t do anything about it,” said Christine Löhde, 57, whose company car burned up in front of her physical therapy center on Neuköllner Strasse, in a complex that includes a pet food store, a preschool and apartments. “They are understaffed, and the city says it’s too poor to do anything about it.”

Perpetrators are particularly difficult to catch because the crime itself is so simple. Small flammable cubes, of the sort used to light charcoal for barbecues, are placed under one of the car’s tires. By the time the tire is burning, the culprit is blocks away. Add to that the fact that Berlin is a large city, with thousands of miles of streets, and it is a virtual impossibility to patrol all of them at once.