German police have arrested 38 people suspected of involvement in Islamic extremism, in a series of raids.
Many of the arrests were around Frankfurt's railway station
The interior ministry of the western state of Hesse said 33 suspects did not have valid papers and three were wanted in relation to other offences.
The arrests were made in 20 towns and cities across the state.
The raids come days after French police arrested nine people said to be suspected of plotting attacks on targets including Paris' underground.
Giving details of the German raids on Tuesday, Hesse's Interior Minister Volker Bouffier said there was currently no evidence of a concrete threat from Islamic extremists in Hesse and it was not the intention of the authorities to stigmatise Islam.
"The goal of the state-wide search and control action was the pre-emptive combating of criminal Islamic structures," he said.
"These are also used for the support of international extremists or terrorists."