German authorities raided a mosque, an Islamic community center and radical Islamists' flats in cities across Germany on Tuesday on suspicion of having connections to militants in Syria.
The suspects, belonging to the ultra-conservative Salafist movement, are aged between 23 and 36 and police believe they were planning a violent attack although they made no arrests.
“We will not stand by and watch as the terrorist Islamic State death squads in Syria and Iraq get support from Germany,” Joachim Herrmann, interior minister for the southern state of Bavaria, told reporters after detailing the raids.
The raids took place as the United States and Arab allies launched air strikes against Islamic State and al-Qaida militants in Syria.
More than 400 German citizens have traveled to Syria to join Islamic State and the Berlin government this month outlawed the organizationJ, making IS propaganda, symbols and activities illegal.
In Tuesday's raids, police seized computers, hard drives and electronic data from a flat in Fuerth and three flats in Nuremberg in southern Germany, where they also raided a mosque and Islamic center. They also searched a flat in Bonn in west Germany and two flats in Weyhe in the north.
Investigators believe the suspects had raised money to send an ambulance from Germany to Syria. Once in Syria the vehicle was converted for military use with a mounted gun. The suspects also helped send vehicles to Syria for use by Islamic State, Herrmann said.
Salafists make up only a tiny proportion of Germany's Muslim population of 4 million but have clashed with police and far-right groups. German intelligence says the number of Salafists grew to 5,500 in 2013 from 4,500 the year before and it is keeping tabs on them.
Last Friday German Muslims at more than 2,000 mosques condemned the actions of Islamic State in a nationwide day of prayer and vowed to stem the tide of youngsters heading to join radical militants in Syria and Iraq.
Germany is also set to prosecute at least 30 suspected jihadists who have returned to Germany over their activities in Syria.