A German newspaper which reprinted cartoons from French magazine Charlie Hebdo was firebombed this weekend, raising fears of further attacks in the country.
Two people were arrested after rocks and a burning object were thrown into an office of the Hamburger Morgenpost daily newspaper in Hamburg, setting documents on fire, Reuters reported.
The newspaper had printed satirical cartoons from French newspaper Charlie Hebdo, whose offices were attacked on Wednesday when armed Islamist gunmen shot dead 12 people and injured more.
There were no injuries as the Hamburg newspaper said there were no people in the building at the time of the arson attack.
Investigators are probing whether there is any connection with the cartoons.
The attack comes ahead of a mass rally planned against 'Islamisation' in the German city of Dresden, where far-right anti-Islam protests have been growing rapidly.
The Patriotic Europeans Against the Islamisation of the West (PEGIDA) group holds weekly rallies, which attracted a record 18,000 people in December, although anti-racism protests opposing it drew in far more.
Meanwhile, over a million people took to the streets of Paris today for a unity rally which was the biggest demonstration in French history, according to the government.
German Interior Minister Thomas de Maiziere said he was worried about similar attacks to the Charlie Hebdo massacre in his country.
He considers around 260 people in Germany are considered to be dangerous Islamists, Reuters reported.
"I am very concerned about well-prepared perpetrators like those in Paris, Brussels, Australia or Canada," he told the newspaper Bild am Sonntag.