ISTANBUL - Turkey on Thursday ordered the seizure of the assets of 187 businessmen suspected of links to US-based Islamic preacher Fethullah Gulen, accused by Ankara of masterminding last month’s attempted coup, state media reported.

Police launched a vast operation in the economic capital Istanbul and other provinces into the alleged Gulen-linked companies - the biggest crackdown on business since the July 15 failed putsch, the Anadolu news agency said. Local media said around 1,000 police took part in raids at 204 addresses in 18 provinces, including simultaneous operations at around 100 sites in Istanbul.

Prosecutors issued arrest warrants for 187 suspects including the CEOs of leading companies, with the Istanbul chief prosecutor’s office ordering their assets to be seized, state-run Anadolu said.

Sixty of the suspects were detained including Omer Faruk Kavurmaci, CEO of the Aydinli Group clothing retailer, it added.

The raids targeted major companies like Aydinli - present in 39 countries with 476 stores and 3,500 employees - as well as fashion company Eroglu, with 14,150 employees globally, and bakery Gulluoglu Baklava, reports said.

Gulen, a reclusive cleric who has lived in self-exile in the United States since 1999, vehemently denies he was behind the coup attempt.

With a powerful network of influence in institutions such as the judiciary and police as well as the media, the former ally of President Recep Tayyip Erdogan has long been accused of running a “parallel state” in Turkey.

Tens of thousands of his alleged supporters have been detained or sacked in a sweeping post-coup purge that has worried Ankara’s Western partners. Aydinli CEO Kavurmaci condemned the failed coup in a statement on the website of the group, which also has interests in the construction sector. “We support our president, our prime minister and our government elected with the will of the people,” he said.

Police have seized books by Gulen and a plaque awarded by the preacher to Kavurmaci during a search of the CEO’s office, Anadolu said. Rizanur Meral, president of the Turkish Confederation of Businessmen and Industrialists (Tuskon), is also among the suspects, the news agency reported.

Founded in 2005, Tuskon has 55,000 members and is accused by the government of financing pro-Gulen activities.

The suspects are accused of “membership in a terrorist organisation” and “financing the activities” of Gulen, according to the private Dogan news agency. In a similar operation on Tuesday, Turkish police raided dozens of companies in Istanbul in search of 120 suspects including CEOs. Around 100 people were detained.

That operation targeted Akfa, largely involved in construction, and the A-101 supermarket chain which has 6,300 stores across Turkey, reports said.

Turkey has imposed a three-month state of emergency which it says is needed to hunt down the coup plotters, and Erdogan has vowed to eradicate businesses, charities and schools linked to Gulen, calling them “nests of terror”.

Ankara wants Washington to extradite Gulen to face trial back home, indicating that any failure to deliver him will severely damage ties.

US Vice President Joe Biden will travel to Ankara next week, the White House said, in the highest ranking visit to Turkey by a Western official since the coup.

Turkish prosecutors this week demanded two life sentences and an additional 1,900 years in prison for the preacher.

In a 2,527-page indictment, the so-called Fethullah Terror Organisation - the name Ankara gives the group led by Gulen - is accused of collecting funds from businessmen and channeling the “donations” to the US through front companies, among other accusations.

Gulen, 75, once a close ally of Erdogan and the ruling Justice and Development Party (AKP), has strongly denied all of the government’s accusations.

Prime Minister Binali Yildirim said Wednesday that 40,029 state employees had been detained in the post-coup crackdown, with 20,335 remanded in custody.

On Wednesday authorities began releasing some 38,000 prisoners not linked to the coup to relieve pressure on prisons overcrowded with putsch suspects.

More than 5,000 civil servants have been dismissed and almost 80,000 others suspended, Yildirim said in an interview with TRT public television.