ANKARA (Reuters) - Turkish authorities issued detention warrants for 189 lawyers as part of an investigation into followers of a Muslim cleric accused of orchestrating last July’s attempted coup, state-run Anadolu news agency said on Wednesday.

The scope of purges that have also seen more than 130 media outlets shut down and some 150 journalists jailed has unnerved rights groups and Western allies, who fear President Tayyip Erdogan is using the coup bid as a pretext to muzzle dissent.

The 189 suspects were sought by anti-terrorist police across eight provinces including Istanbul for alleged links to the network of U.S.-based cleric Fethullah Gulen, the agency said. He has denied involvement in the failed putsch.

Police have so far detained 78 of the lawyers, some believed to be users of ByLock, an encrypted messaging app the government says was used by Gulen’s followers.

Since the July coup attempt, authorities have jailed pending trial 50,000 people and sacked or suspended 150,000, including soldiers, police, teachers and public servants, over alleged links with terrorist groups, including Gulen’s network.

Erdogan says the crackdown is necessary due to the gravity of the coup attempt in which 240 people were killed.