Thirteen people suspected of recruiting fighters for radical Islamic groups in the Middle East have been arrested by police in Austria, who stormed mosques and homes in a cross-country dawn raid on Friday.
Around 500 officers were involved in the arrests in Vienna, the southern city of Graz and Upper Austria province, which follows two years of surveillance of the suspects.
The arrested individuals were also being investigated for helping to finance the Islamic State, according to local media.
Austrian privacy laws prevent suspects from being named; however, media reports pointed to a Vienna-based Bosnian preacher as the main suspect.
He was among those taken into custody following the raids which began at 4am.
Austria's Interior Ministry says that around 150 people have left Austria to join radical groups in Syria and Iraq such as the Islamic State.
Nine Chechens are currently awaiting trial after being arrested by Austrian police in August for planning to wage jihad with the extremist fighters in Syria.
Last month two teenage girls who ran away from home to join the terrorist group said they wanted to return to Austria.
Samra Kesinovic, 17, and friend Sabina Selimovic, 15, are thought to be married, pregnant and living in the IS stronghold of Raqqa in northern Syria.
In April the friends left a note for their parents that read: "Don't look for us. We will serve Allah, and we will die for him."
Their social media accounts suggested that they were enjoying their new lives, but Austrian officials later told the media that at least one of them had been in contact with family members expressing a desire to leave. However they are said to be fearful of the consequences, both from IS and the authorities in their home country.
Two more Austrian teenage girls are thought to have left home earlier this month.
Sisters Viktoria, 16, and Violetta, 17, whose full names have not been released, were believed to be in Turkey two weeks ago after their mother received a phone call from the pair.
In June, Austria's Federal Office for the Protection of the Constitution and Counterterrorism issued a warning about the rise of extremism in the country.
It said: "Religiously motivated extremism and terrorism — above all of Islamic character — as well as Salafi-jihadi groups continue to present a great potential threat…The number of young radicalized followers of violent Salafism continues to rise.
"In this context, the conflict in Syria is of urgent relevance for Austria, since systematic efforts are being made within [Austria] to radicalize and recruit people for the war in Syria…The conflict in Syria has become very popular among violent extremist Salafis.
"The spectrum of recruits to the conflict in Syria is broadly ethnically diverse. The motivation, however, seems to be uniformly jihadi."
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