Years of heavy security presence in Russia's Caucasus region to battle internal terrorist threats have likely only created more terrorists, fueling recruits for the Islamic State group, according to an Associated Press report Wednesday. As Russia increases its airstrikes against ISIS in Syria, domestic worries grow about fighters who may return home to Russia and sow terrorism there.

"The fact that he left for Syria — the police are to blame. They wouldn't leave the boy alone," the father of an ISIS recruit from the region told the AP.

Russia has had a heavy security presence in its North Caucasus region since the separatist wars that were waged in Chechnya in the 1990s. The region is predominantly Muslim. Terrorists from the region have carried out domestic attacks and sieges in the past, including the 2002 Moscow theater hostage crisis and the Beslan school siege in 2004. Each attack left more than 100 dead.

Russia is doing little to stop young men from leaving the region to join ISIS, and the high security presence in regions like Dagestan are helping to fuel ISIS’ recruiting efforts, the AP found. Police detentions in the region can include fingerprinting as well as providing DNA samples.

"If someone goes to the wrong mosque, he knows that when he leaves he could be taken to the police station, where he would be questioned, he would be fingerprinted for the 20th time," said Magomed Magomedov, the deputy editor-in-chief of Dagestan's weekly newspaper. "This system of keeping people on edge alienates and embitters them, and one in 10 may just decide to take radical steps and go to Syria."

Many people in the city of Komsomolskoye visited by AP said they knew someone who had left the region to join ISIS. Russia has estimated that 3,000 of its citizens have left the country to join ISIS. Approximately a third of those came from Dagestan in the Caucasus region.

Russia has increased the arrests of migrants who may have ties to terror groups in recent weeks. The Kremlin has said that almost 2,000 people are being held across Russia for terrorism or extremist acts.

ISIS has directly threatened Russia with a video released by the group saying they would spill blood in Russia. An affiliate of ISIS claimed responsibility for the downing of a Russian Metrojet flight over Egypt in October that resulted in the death of all 224 people on board. Russia began airstrikes in Syria targeting ISIS at the end of September.