Two graduates of Turkish schools in Turkmenistan who were arrested in response to Turkey’s crackdown on Gülenists have died in prison there in the past year, Asia-Pacific news outlet The Diplomat reported on Wednesday.

The schools had been linked to Turkish cleric Fethullah Gülen, who Turkey blames for a 2016 failed coup, but were taken over by the government in 2011.

Gülen-affiliated schools were established throughout Central Asia in the mid-1990s and eventually spread to more than 100 countries around the world. Those in Turkmenistan were widely regarded as the best in the country, according to the Diplomat.

“The teachers are good people. They came to the country when it was really in a devastated state [and] had a big impact,” said Myrat, a graduate who now lives in the United States. “[The schools] moved the country 20, maybe even 40 years forward.”

Graduates were seen as some of the country’s most skilled people, and include many celebrities, successful business people, and top bureaucrats. “They’re well-educated. They speak at least three languages. They’re really good at chemistry, biology, mathematics,” Ruslan Myatiev, head of Netherlands-based Turkmen.news, told the Diplomat.

The schools were established, according to the Diplomat, thanks to Muammer Türkyılmaz, a Turkish member of the Gülen movement who was close to Turkmenistan’s strongman leader, Saparmyrat Niyazov, known as Türkmenbaşı. Türkyılmaz was appointed Turkmenistan’s deputy minister of education in 2007, said the Diplomat.

Turkish billionaire businessman Ahmet Çalık was said to be Niyazov’s closest advisor, and helped establish a Turkmen version of the Gülen-aligned newspaper Zaman. Çalık’s conglomerate Çalık Holding was previously headed by Turkish President Recep Tayyip Erdoğan’s son-in-law Berat Albayrak, who is now Turkey’s minister of finance and treasury, according to the Diplomat.

Some 600 Turkish firms are registered to work in Turkmenistan, according to the Turkish government, while Ashgabat has for years been the top buyer of Turkish arms. Many Gülen-linked businessmen helped develop relations between Turkey and Turkmenistan, until the Turkmen government nationalised most of the schools starting in 2010.

“Before the rupture between Gülen and Erdoğan, the Turkmen government, considering that the Turkish schools had already formed enough new elites, had itself decided to close the schools,” said Bayram Balcı, a researcher specialising in Islamic movements in Central Asia at Istanbul’s French Institute for Anatolian Studies.

Months after the failed 2016 coup in Turkey, about 100 graduates of the schools were arrested in Turkmenistan. A few months later, 18 of them were convicted of participation in a criminal organisation and given lengthy prison sentences.

Around this time, Turkey requested the extradition of Türkyılmaz, who it accused of being the Gülen network’s head of operations for Asia. “Turkmenistan was one of the first countries to take the bravest steps before and after the coup attempt,” Turkish Foreign Minister Mevlüt Çavuşoğlu said last year.

Dozens of the prisoners were held in isolation for a year during pre-trial detention, before another 10 were sentenced to prison, according to Rachel Denber, deputy director of Human Rights Watch’s Europe and Central Asia. Their trials were likely a sham and signs after their release suggested they had been beaten while in custody, according to Denber.

According to Myrat, 38-year-old businessman Akmyrat Soyunov died in prison last October, and 37-year-old teacher Eziz Hudayberdiyev died in June.

“It’s so sad,” said Myrat. “And for what? Going to a school, reading some books.”