Germany's Interior Minister, Otto Schily, has banned 16 organisations linked to a jailed Turkish militant once known as the Caliph of Cologne.
The authorities used new anti-terror legislation passed after 11 September.
The move follows a series of raids nationwide in five federal states across Germany.
Over 100 properties were searched, including mosques, Islamic associations and private apartments.
No arrests were reported.
The organisations' bank accounts were frozen as the ban came into effect.
'Security danger'
The Caliphate State organisation, run by Muhammad Metin Kaplan, wants to overthrow Turkey's secular regime and impose a radical Islamic state.
It was itself banned, along with 20 affiliates, last December.
That was the first time a religious association had been closed down under the new anti-terror powers.
The leader of the 1,000-strong organisation is still in prison for his part in the murder of an opponent within the organisation.
Germany's Interior Ministry said in a statement that the group endangered Germany's internal security and German foreign policy interests.