The Turkish newspaper Hurriyet reported on Thursday that 830 Europeans have been arrested and deported back to their home countries over the last two years after attempting to cross over from Turkey into Syria to join Islamic State forces.

According to the report, which does not cite official sources, Turkey deployed special units at border-crossings, airports and bus and train terminals, aiming to stop aspiring jihadis from joining the extreme Islamists forces fighting in Iraq and Syria.

Units stationed at Istanbul's two airports, Sabiha Gökçen Airport and Atatürk Airport, held 240 passengers on suspicion of intending to join Islamic State, 56 of which deported to their country of origin, said the report. The rest were released.

Islamic State controls large parts of northern Syria, on the border with Turkey. According to Hurriyet, a Syrian village by the name Atmeh near the Turkish border is used by Islamic State as a main rallying point for potential jihadis and as a training center. Turkish anti-terrorism units have thus increased their presence in the area.

Hurriyet also reported that several European countries have recently started sharing information about their citizens who are suspected of intending to join the Syrian jihadis. According to the report, which again does not cite a source, Germany, Britain, France, Holland and Belgium, among others, have provided Turkey with information about 4,700 suspected jihadis.

Citing anti-terror and intelligence units, Hurriyet reported that some 1,000 Turkish citizens are believed to have joined Islamic State forces.

The presence of Western-educated fighters in what was formerly called the Islamic State in Syria and Iraq, gained particular attention after the release of a video showing the recent beheading of U.S. journalist James Foley by a masked executioner with a London accent. But European nations have been worrying for quite a while about their citizens joining the radical group which declared the birth of an Islamic State in June.

The countries that apparently export the most Islamic State fighters are France (700 men, according to President Francois Hollande); the United Kingdom (at least 500, according to the Soufan Group, an international strategic consultancy firm); Germany (about 320, according to local news reports); and Belgium (approximately 350, according to The New York Times).