The London-based Syrian Observatory for Human Rights (SOHR) claimed on Monday that at least 85 militants from ISIS have moved from Syria to Turkey with their families, the Diken news website reported.
According to SOHR, they paid money to smugglers to cross the Turkish-Syrian border and traveled through both Turkish and Kurdish-held territory in northern Syria.
SOHR also claimed that they had paid between $10,000 and $50,000 to the smugglers and were carrying huge amounts of cash themselves.
According to experts, as the fight against ISIL winds down, radical militants have begun to return to their home countries or at least move to other places such as Turkey.
Several international reports have predicted that Turkey would become a safe haven for ISIL militants after the Syrian civil war.