Turkish authorities arrested 21 people suspected of belonging to ISIS on Friday in raids on four Turkish cities, including Istanbul, according to Anatolia news agency.
The reported counterterrorism operation took place in Istanbul, Izmir, Urfa in the southeast of the country, and Mersin in the south. The operation was one of the largest police operations against ISIS in Turkey, which considers ISIS a terrorist organization.
The agency said that among the suspects were four foreigners preparing to travel to Syria to fight alongside ISIS.
Turkey is considered a key passage for foreign fighters wishing to travel into Syria to join ISIS.
Translated and edited by The Syrian Observer