Former İstanbul police chief Hüseyin Çapkın has been detained for alleged involvement in a failed military coup attempt on July 15.

Detention warrants have been issued for four administrative officials including Çapkın, who served as İstanbul chief of police between 2009 and 2013, as part of an investigation launched by the İstanbul Chief Public Prosecutor’s Office into the attempted coup.

Çapkın was detained in the western province of İzmir on Tuesday morning. The other three people, one governor and two district governors, were also detained on Tuesday.