A German newspaper in the northern port city of Hamburg that reprinted Muhammad cartoons from the French satirical paper Charlie Hebdo was the target of an arson attack early on Sunday, police said.

"Rocks and then a burning object were thrown through the window," a police spokesman said. "Two rooms on lower floors were damaged but the fire was put out quickly."

The regional daily newspaper, Hamburger Morgenpost, had splashed three Charlie Hebdo cartoons on its front page after the massacre at the Paris publication, running the headline "This much freedom must be possible!"