Turkish authorities have issued detention warrants for 216 people, including former finance ministry personnel, suspected of having links to last year's failed coup attempt, the state-run Anadolu news agency said on Wednesday.

It said 17 former finance ministry personnel had been detained so far and another 65 were sought over alleged links to Gulen's network, Anadolu said.

Separately, authorities carried out operations across 40 provinces targeting “private imams” believed to be recruiting members to the network of US-based cleric Fethullah Gulen from Turkey's armed forces.

Ankara blames Gulen for orchestrating the 15 July coup attempt last year and has repeatedly demanded the United States extradite him, so far in vain. Gulen denies involvement.

In the aftermath of the coup, more than 50,000 people have been jailed pending trial and some 150,000 have been sacked or suspended from their jobs in the military, public and private sector.

In pictures: Turkey coup attempt Show all 17 1 /17 In pictures: Turkey coup attempt In pictures: Turkey coup attempt Turkish President Erdogan attends the funeral service for victims of the thwarted coup in Istanbul at Fatih mosque on July 17, 2016 in Istanbul, Turkey Burak Kara/Getty Images In pictures: Turkey coup attempt Soldiers involved in the coup attempt surrender on Bosphorus bridge with their hands raised in Istanbul on 16 July, 2016 Gokhan Tan/Getty In pictures: Turkey coup attempt A civilian beats a soldier after troops involved in the coup surrendered on the Bosphorus Bridge in Istanbul, Turkey, 16 July, 2016 REUTERS/Murad Sezer In pictures: Turkey coup attempt Surrendered Turkish soldiers who were involved in the coup are beaten by a civilian Reuters In pictures: Turkey coup attempt Soliders involved in the coup attempt surrender on Bosphorus bridge Getty In pictures: Turkey coup attempt Supporters of Turkish President Recep Tayyip Erdogan wave flags as they capture a Turkish Army vehicle Getty In pictures: Turkey coup attempt People pose near a tank after troops involved in the coup surrendered on the Bosphorus Bridge in Istanbul, Turkey, 16 July, 2016 Reuters In pictures: Turkey coup attempt Turkish soldiers block Istanbul's Bosphorus Brigde Getty In pictures: Turkey coup attempt A Turkish military stands guard near the Taksim Square in Istanbul Reuters In pictures: Turkey coup attempt Pierre Crom/Twitter In pictures: Turkey coup attempt Turkish soldiers secure the area as supporters of Recep Tayyip Erdogan protest in Istanbul's Taksim square AP In pictures: Turkey coup attempt People demonstrate in front of the Republic Monument at the Taksim Square in Istanbul Murad Sezer/Reuters In pictures: Turkey coup attempt Turkish soldiers detain police officers during a security shutdown of the Bosphorus Bridge Reuters In pictures: Turkey coup attempt Turkish Army armoured personnel carriers in the main streets of Istanbul Getty In pictures: Turkey coup attempt Chaos reigned in Istanbul as tanks drove through the streets EPA/TOLGA BOZOGLU In pictures: Turkey coup attempt Turkish President Tayyip Erdogan speaks to media in the resort town of Marmaris Reuters In pictures: Turkey coup attempt Supporters of President Erdogan celebrate in Ankara following the suppression of the attempted coup Reuters

The extent of the purges has unnerved rights groups and Turkey's Western allies, who fear President Recep Tayyip Erdogan is using the abortive putsch as a pretext to stifle dissent.

The government, however, says the measures are necessary due to the gravity of the threats it is facing following the military coup attempt, in which 240 people were killed.