Police in Turkey arrested dozens of suspected ISIS members in a raid in the city of Istanbul, the private Dogan news agency reported on Tuesday. Counter-terror police raided 19 addresses in over a dozen districts late on Monday, detaining 54 suspects who were taken for interrogation at the citys police headquarters, it said. All the detainees are foreign nationals, revealed the police without offering more details. Police suspect that they were planning to travel to neighboring Syria. Turkey staged multiple crackdowns on the terrorist group which has been blamed for a series of attacks, including one at an Istanbul nightclub over New Year 2017 which claimed 39 lives. Turkish operations against ISIS suspects intensified at the end of last year on the anniversary of the nightclub shooting. In April, police detained four key ISIS members including a so-called emir in charge of Syrias Deir Ezzor province.