ANKARA (Reuters) - Turkish authorities ordered the arrest of 249 foreign ministry personnel over suspected links to the network of a U.S.-based cleric accused of orchestrating an attempted coup in 2016, broadcaster NTV said on Monday.

Authorities have carried out regular operations against the alleged followers of Fethullah Gulen, who has lived in self-imposed exile in Pennsylvania since 1999, since the failed coup attempt on the night of July 15, 2016. Gulen denies allegations he was behind it.

The Ankara chief prosecutor’s office said it ordered the arrest of 249 members of Turkey’s foreign ministry after investigations found that they had committed irregularities in the ministry’s past entrance exams, NTV reported.

It said 78 suspects had been detained so far in operations across 43 provinces and that police were seeking the rest.

More than 77,000 people have been jailed pending trial, while some 150,000 civil servants, military personnel and others have been sacked or suspended from their jobs as part of the post-coup purges.

Rights groups and Turkey’s Western allies have voiced concerns over the crackdown, saying President Tayyip Erdogan has used the abortive putsch as a pretext to quash dissent. The government has said the security measures were necessary due to the gravity of the threat Turkey faces.