istanbul turkish police launch operations track 42 university staff istanbul marmara university allege link last year fail coup attempt police source say friday far 22 people detain operation police source say add suspect believe contact network u.s.-based cleric fethullah gulen ankara accuse orchestrate abortive putsch july 2016. gulen deny involvement denounce coup since fail coup authorities arrest around 50,000 people pending trial 150,000 people include teachers judge soldier sack suspend job crackdown alarm right group turkey western ally fear government use coup pretext quash dissent government say crackdown necessary give severity security threat 240 people kill last year coup attempt turkey hunt 42 university staff post-coup crackdown source