State prosecutors in Turkey have issued arrest warrants for 154 people, including navy officers, teachers, and union members, for alleged links to a US-based Turkish figure accused of organizing a coup against Ankara in 2016.

Turkish police forces launched operations across five provinces across the country to arrest 16 naval officers — seven of them serving and nine previously expelled from the armed forces — over alleged connections with cleric Fethullah Gulen, state news agency Anadolu reported on Friday.

The Ankara chief prosecutor’s office further conducted a separate investigation, ordering the detention of 66 teachers from across the country who had been previously dismissed from their jobs over links to what the government describes as Gulen’s movement.

The report also added that 72 officials from a labor union confederation, which had already been shut down under a government order, were set to be taken into custody as well in a third investigation into the alleged plot across more than a dozen provinces in Turkey.

Ankara, meanwhile, has rejected concerns expressed by international rights organizations over the massive crackdown on people suspected of having links with Gulen, insisting that threats posed by his network across Turkey could only be neutralized through such wide-scale purging of government institutions allegedly infiltrated by his elements.

Gulen, a former political ally of Turkish President Recep Tayyip Erdogan, has lived in self-imposed exile in the US state of Pennsylvania since 1999 and has persistently denied accusations of involvement in the failed coup attempt in July 2016, which killed more than 240 people.

Following the coup, Ankara launched a massive crackdown that has so far led to the imprisonment of more than 50,000 people pending trial for alleged ties to the Gulen network.

Nearly 150,000 other people have also been either dismissed or suspended from their posts in the military, as well as in the public and private sectors.