ISTANBUL - Turkish authorities began rounding up 155 suspected followers of the cleric Fethullah Gulen on Friday, police and media said.Ankara accuses Gulen, who lives in the United States, of masterminding a failed coup in July 2016, a claim he denies. Since the coup attempt, the authorities have arrested thousands of his suspected followers and fired thousands more.Friday's roundup included warrants for 55 employees in 13 provinces of Isik Publications, a publishing company that printed Gulen's books, Istanbul police said.Warrants were also issued for 38 former police officers in six provinces who were accused of being members of Gulen's purported network, the state-run news agency Anadolu reported. Twenty-four had been detained, it said.In addition, police targeted 62 executives of five labor unions in a third operation spread across seven provinces, Anadolu said. Thirty-eight had been detained, it said.The labor unions were part of Aksiyon Is Confederation, an association of unions that was shut down over suspected links to the Gulen network.In the 18 months through December 2017, nearly 160,000 people have been arrested and 152,000 civil servants sacked as part of a post-coup crackdown, according to a report published by the United Nations on Tuesday.The UN urged Turkey to end its state of emergency, which was declared after the coup and has been extended six times. It accused Ankara of mass arrests, arbitrary sackings, collective punishment and torturing detainees.Turkey's foreign ministry said the report was filled with unfounded allegations and compared the criticism to propaganda from militant groups.The crackdown has also been criticized by Turkey's Western allies, who accuse President Tayyip Erdogan of using the failed putsch as a pretext to quash dissent. Turkey says the measures are necessary to combat threats to national security.