The German government says it is taking "extremely seriously" an initiative by a radical Salafist group to give away millions of translations of the Koran on German city streets.
The campaign organized by a Salafist activist and businessman, Abu Nagie, and his group, The True Religion, began in October, but the controversy surfaced only recently.
Salafists are an ultraconservative faction within Sunni Islam.
German security authorities say most violent Islamists are adherents of Salafism.
Politicians across the political spectrum have accused Nagie's group of abusing religious freedom for propaganda and to recruit followers.
Security authorities say there are about 2,500 Salafists in Germany.
Nagie's group has said it plans to give away some 25 million copies of the Islamic holy book in city pedestrian zones in Germany, Austria, and Switzerland.
Based on reporting by dpa and AFP