ANKARA – A Turkish prosecutor on Tuesday issued an arrest warrant for 21 suspects over their alleged links to a network accused of orchestrating a coup attempt in 2016.

The warrant was issued as part of an investigation into the Gulen Movement and targeted three lawyers, along with students who were dismissed from the Faculty of Security Sciences of the Police Academy Presidency and the Police College, the prosecutor’s office of the capital Ankara said.

The Turkish government accused Gulen Movement of infiltrating into the state bureaucracy and attempting a coup on July 15, 2016. Simultaneous operations are carried out by the police to detain the suspects in six cities, it said. The Gulen movement, which mainly runs schools around the world, is a community of people named after Muslim preacher Fethullah Gulen who is regarded by followers as a spiritual leader.

Ankara accuses U.S.-based Fethullah Gulen of masterminding the attempted coup, in which at least 250 people were killed. Turkey requests the extradition of Gulen, but Washington is reluctant to extradite the self-exiled Islamic cleric, saying that Ankara has not presented sufficient evidence against him. The Turkish government has launched a massive crackdown on suspects with links to the network after the coup attempt.