Berlin police are offering euro5,000 ($7,180) to anyone able to help them find vandals who set fire to 18 cars parked in residential neighborhoods overnight.
It was the second consecutive night in Berlin to see a jump in arson attacks, after vandals torched 11 cars on Tuesday evening.
Berlin police believe the arsons are politically motivated, possibly linked to Leftist extremists. They have rejected any links to the riots in London.
The Wednesday attacks bring the number of cars burned so far this year in Berlin to more than 300 _ more than the total torched in 2010.