Istanbul (CNN) The call to prayer at Emine Inanc mosque brings together immigrants who have found sanctuary in Istanbul's working-class Zeytinburnu neighborhood.

With no room inside the overcrowded mosque, dozens of worshippers spill onto the street. For some, like Ishqiyar Abudureyimu, praying openly would have been unimaginable just a few years ago when he was living in China.

The 27-year-old is among thousands of Uyghurs, a predominantly Muslim ethnic minority from Xinjiang province in western China, who have sought refuge in Turkey after escaping Beijing's brutal crackdown against the group.

Ethnic and religious ties between Turkey and the Uyghurs, the immigrants say, have made building new lives in Istanbul easier for them.

Uyghurs, who call their homeland "East Turkestan," speak a dialect of Turkish and, like the Turks, are considered ethnically Turkic.

Dozens of Uyghur shops and restaurants line the streets of Zeytinburnu, a small neighborhood near Istanbul's international airport. Most shop signs are in the group's native script and language which they say was banned in Xinjiang province.

In a rundown building, children attend after-school classes to learn their mother tongue. Boys and girls crammed into small classrooms recite the Uyghur alphabet which most are learning for the first time.

"We are more comfortable than we were in our home country," says Abudureyimu, who has lived in Turkey since 2014. "I can practice my religion freely, speak my language freely," he adds. "In Turkey I saw that a man can live freely, in peace. We are free here."

Missing relatives

However, Abudureyimu is all too aware that back at home, oppression against Uyghurs continues. Seated in an Istanbul Uyghur restaurant, he lays out more than two dozen photographs of loved ones who he says have disappeared in China. He arranges the images along a straight line, then holds them up and introduces each of his family members.

"My father ... my mother ... my sister," he tells CNN, his voice fraught with emotion as he identifies them.

Abudureyimu says he does not know the whereabouts of his family or even if they are alive, but he believes Chinese authorities detained them. He adds that the crackdown against Uyghurs targeted his family for years but that it worsened after he fled. Many other families whose relatives left China have also come under increased pressure from authorities, he said.

Chinese authorities did not respond to CNN's request for comment.

After fleeing persecution, many Uyghur children are learning their native language for the first time in Turkey.

An estimated 1 million Uyghurs are being held in camps across eastern China as part of the crackdown, according to a 2018 US congressional report.

The Chinese government has never explained the disappearances, which began in 2017, nor said how many people are being held in the camps, which they insist are "vocational training centers" that local "students" willingly attend.

"The local Chinese government is taking these preventative counter-terrorism and de-extremization measures to protect more people from being devoured by terrorism and extremism," Chinese Foreign Ministry spokesperson Hua Chunying said in December 2018.

In early January, Chinese authorities took some foreign diplomats and journalists on a carefully supervised tour of some of the "vocational education centers."

Detainees were seen taking language courses in standard Mandarin Chinese, painting, performing ethnic dances and even singing the song, "If you're happy and you know it, clap your hands," according to a Reuters report.

"All of us found that we have something wrong with ourselves and luckily enough the Communist Party and the government offer this kind of school to us for free," one Uyghur inmate told journalists during the tour.

Ishqiyar Abudureyimu holds up a picture of his mother outside Istanbul's Hagia Sophia mosque. He says this is the last time he saw her and that she has disappeared since she returned to China.

But China's claims don't answer the Uyghur community's questions about their disappeared loved ones.

Diaspora members see solidarity protests as their main chance to support their families back home. Dozens of Uyghurs gather in central Istanbul, waving Uyghur nationalist flags and carrying photographs of missing parents, siblings and spouses. Some hold whole family portraits.

'"Those photos are of my relatives and Uyghur celebrities," said one protester, philosophy student Fazilet Gurec. "We lost contact three years ago."

"Our expectation is to know what happened to them and what is their situation now," she added.

One of the last photographs in Abudureyimu's collection back at the Uyghur restaurant is of his mother sitting outside Istanbul's Hagia Sophia mosque. He claims she was detained after she returned from a 2015 visit to Turkey.

He also shows a picture of his family home, which he hasn't seen since he fled western Xinjiang. Recently, he discovered the photograph on social media -- it was blanketed with snow and appeared abandoned.

Solidarity in Turkey

A sense of solidarity with the Uyghurs is evident in Turkey, but trade ties with China have tempered Ankara's response to their plight. For the most part, Turkey has opened its doors to Uyghurs escaping persecution, but remained largely silent about the brutal crackdown.

However, Turkey's foreign affairs ministry issued an explosive statement in February slamming the Chinese government for undertaking a deliberate campaign to eradicate "the ethnic, religious and cultural identities of the Uyghur Turks and other communities in the region."

It condemned the camps where China holds Uyghurs as a "great shame for humanity," adding that hundreds of thousands of members of the group were subject to "torture and political brainwashing" in the camps.

A Uyghur restaurant displays the group's native script, which is banned in China.

In a statement, China's Ministry of Foreign Affairs called on Turkey to withdraw its "groundless accusations," adding that both countries were facing "severe anti-terrorism situations." The statement said China's camps were open to the world.

"We have invited more than 12 countries' ambassadors to China and foreign correspondents, including the Turkish ones, to visit Xinjiang," the statement said.

Turkey's statement came after reports claimed the popular Uyghur folk musician Abdurehim Heyit had died in jail in China. The Turkish Foreign Ministry said it learned that he had died. Beijing denied the reports, broadcasting what it claimed was video footage proving Heyit was still alive.

In response, Uyghurs in Turkey joined a #MeTooUyghur social media campaign, with hundreds taking to the streets demanding China release proof-of-life videos of their disappeared relatives.

A Uyghur stand in Istanbul pays tribute to disappeared people, believed to be detained in Chinese concentration camps in western China.

"Every morning I wake up and hope not to receive a sad news," says Abudureyimu. "My dad, mom, brothers, grandfathers ... I live in fear of receiving news of their death."

The Uyghurs want China to be held to account for the disappearance of their missing relations. Abdul Melik, a member of Istanbul's Uyghur community told CNN: "There are some individual voices, some individual countries (speaking out), but the whole world is in deep sleep now."