Xinjiang, China(CNN) It was supposed to be a routine trip home to Xinjiang for Mamutjan Abdurehim's wife and two children.
That was five years ago. He says he hasn't seen them since.
Mamutjan's wife Muherrem took their daughter and son from Malaysia back to the region in western China to get a new passport in December 2015. They remain trapped there, he said, caught up in the sweeping government crackdown against Muslim minorities that has reportedly seen up to 2 million people arbitrarily detained in vast camps across Xinjiang.
China has denied the allegations of human rights abuses in the region, saying the camps are necessary to prevent religious extremism and terrorism.
Mamutjan said his family, who are ethnically Uyghur, are unable to leave China, while he would be at risk of being detained or imprisoned if he returned. He is now living in Adelaide, Australia.
This week, a CNN team tracked down Mamutjan's 10-year-old daughter Muhlise at her paternal grandparents' home in the city of Kashgar, in southern Xinjiang.
When asked if she has a message for her father, whom she hasn't spoken to since 2017, Muhlise began to cry. "I miss him," she said.
When Mamutjan watched the video from his home in Adelaide, he struggled to fight back his tears.
"I can't believe how tall (my daughter) is now ... What kind of country does this to innocent people?" he said.
In a new report released Thursday, Amnesty International estimated there may be thousands of Uyghur families like Mamutjan's worldwide, parents and children who have been separated for years as a result of the Chinese government's tightening grip on Xinjiang.
Under the leadership of the country's all-powerful President Xi Jinping, Muslim minorities in Xinjiang have allegedly been subject to a government-engineered program of mass incarceration, forced indoctrination and even sterilization.
According to the Amnesty International report, some parents who fled the region in the early days of the crackdown have been unable to reunite with their children. Others, like Mamutjan, found themselves on opposite sides of the ocean by accident, and now fear returning to Xinjiang.
Alkan Akad, a China researcher at Amnesty International, said the separation of parents and children isn't all accidental. In some cases, it can be a deliberate tactic by authorities.
"The Chinese government wants to gain a leverage over the Uyghur population residing abroad, so that they would be able to stop them from engaging in activism and speaking out for their families and their relatives in Xinjiang," said Akad, who authored the new report.
Speaking at a news briefing on March 15, Chinese Foreign Ministry spokesman Zhao Lijian said accusations of human rights abuses in Xinjiang were "baseless and sensational."
"Xinjiang-related issues are not human rights issues at all. They are in essence about countering violent terrorism, radicalization and separatism," he said.
The Chinese government has not responded to CNN's detailed questions on any of the families mentioned in the article, or on the scale of the family separations between Uyghurs in Xinjiang and abroad.
The last time that Mamutjan said his family were all together -- him, his wife and their two children -- was in Malaysia in 2015.
Back then, Mamutjan said he was studying for his doctorate degree in Muslim World Studies, with a full scholarship, while his wife, Muherrem was learning English. He said his daughter Muhlise was in kindergarten and "very active," always running around everywhere, playing in parks and on the university campus. His son was only six months old.
"We were quite happy. We had no major troubles in life," he said.
In December that year, Mamutjan said, his wife went back to Xinjiang with the two children. According to Mamutjan, she had lost her passport and the Chinese embassy in Malaysia had refused to issue her a new one unless she went back to her hometown of Kashgar.
Her passport was renewed in 2016, but Mamutjan said his wife wasn't able to leave immediately due to some financial issues. Then, around the beginning of 2017, her travel documents and those of the children were confiscated by authorities.
A few months later, he said his wife vanished. "I was in constant contact with my wife before April 15, 2017. We would chat daily, video chat with the children. And in the middle of April 2017, she promptly disappeared from (Chinese messaging app) WeChat," he said.
"I called home the following day and my mom told me that she was gone for a short period of time, for a short study course ... And I realized that she was detained."
Mamutjan said he hasn't spoken to his wife since. Initially he was worried his children might have been sent to state-run orphanages, but later received social media videos showing them still living separately with their grandparents from each side.
Worried for his safety, Mamutjan said he left Malaysia and moved to Australia. There was no word from his family for years -- Uyghurs in Xinjiang can be placed in detention for only minor perceived infractions, including for contacting relatives abroad, according to leaked records seen by CNN, and it is common for families still in Xinjiang to cut communications.
Then in May 2019, Mamutjan said, he saw a social media video of his son, then age 4, excitedly shouting, "My mom has graduated!" The Chinese government insists the internment camps are "vocational training centers" and detainees are "students," and Mamutjan took his son's joyful cheering to mean his wife had been released.
Mamutjan said he called his parents, hoping the video was a sign the family's situation had improved, but when his mother answered, she told him there were Chinese Communist Party officials in the house and hung up.
With Mamutjan's permission, CNN journalists visited his parents' house in Kashgar unannounced to see if they could help locate his children -- and find out what happened to his wife.
His daughter Muhlise answered the door in a bright pink shirt and black pants. When showed a picture of Mamutjan, she said: "This is my Dad." She said she knew where her father was but seemed unwilling to talk about her mother's location.
After checking the answer with her grandparents, Muhlise said her mother was at her other grandmother's house but she "can't see her very often." The 10-year-old said she last saw her mother "a month or two ago." She said her brother was not with her but she saw him regularly.
CNN has asked the Chinese authorities about the mother's whereabouts, but has not received a reply. CNN also tried to visit the maternal grandparents' home in Kashgar, but the team couldn't find anyone there -- the door was bolted from the outside.
When Muhlise was asked if she wanted to be reunited with her father, she said, "We can't go ... Our passports were confiscated."
After keeping her composure throughout the arrival of the CNN team, Muhlise began to break down when asked if she missed her father. "I don't have my mom here, and I don't have my dad here either ... I want to be reunited with them," she said. Hearing the question, her grandmother burst into tears.
Mamutjan said he believed the Chinese government was separating parents from their children as a way to intimidate and control Xinjiang's minority groups.
"It's basically a collective punishment for their ethnicity and religion and their unique cultural values," he said. "We did not deserve all of this immense suffering."
Some parents have resorted to desperate measures to try and be reunited with their children.
In 2016, Ablikim Mamtinin and his wife Mihriban Kader said they were forced to flee Xinjiang after she became pregnant with their sixth child. Under China's family planning policies, most families were only allowed to have one child until 2015, although rural ethnic minorities, including the Uyghurs, were permitted up to three in the region. A new policy implemented in 2017 said all urban couples in Xinjiang could have two children, while rural couples could have three.
With each new child, Mihriban and Ablikim said they had been paying fines and bribes to avoid punishments from the authorities. But in 2016, they said they were given a warning from local officials that their patience was at an end.
Ablikim said if they had stayed in Xinjiang any longer, his wife would have been forced to have an abortion. "They would have imprisoned me for having six children," he said.
Mihriban and Ablikim managed to get tourist visas to Italy, giving them a chance to escape and start a new life in Europe. But their travel agent said they weren't able to get visas for all five of their children -- only the youngest. Zumeryem, Yehya, Muhammad and Shehide would have to stay behind.
It was a heartbreaking choice for Mihriban and Ablikim. In the end, after leaving the four children with their grandparents, they left, hoping to be reunited as soon as possible once they were settled in Italy. But as the crackdown intensified in Xinjiang, their relatives in China stopped responding to their calls and emails. The parents heard some of their relatives were detained, which they believed was a result of their decision to leave for Italy. Soon it became impossible to contact anyone -- and they were unable to reach or learn the whereabouts of their four older children for almost four years.
When they finally reconnected in early 2020, and the parents heard how desperate the situation had become inside Xinjiang, they decided it was time to urgently take their children out of China. Visa clearance documents for the four siblings had been approved by the Italian government in 2019, but their passports were about to expire, and the parents say the authorities had been threatening to send the children to a state-owned orphanage.
In June 2020, directed remotely by their parents in Italy and a cousin in Canada, the four siblings -- then aged between 11 and 16 -- traveled from their remote village in Xinjiang all the way to Shanghai, a journey of more than 3,000 miles (4,800 kilometers), in an attempt to get their visas to rejoin their parents in Italy.
The four children took little money and no baggage to avoid suspicion from authorities along the way. But when they went to the Italian consulate in Shanghai to pick up their visas, the children said they were blocked by a Chinese security guard in the lobby of the building, where the consulate sits on the 19th floor.
Emails from consulate officials then directed the children to a different Italian visa office in Shanghai, which eventually rejected their visa application, saying they couldn't recognize the visa clearance documents, and minors needed to be accompanied by adults. They also said the four should apply in Beijing, which was under a Covid-19 lockdown at the time.
The Italian visa office and the Italian consulate in Shanghai have not responded to CNN's inquiries. The Italian Ministry of Foreign Affairs in Rome told CNN "we won't comment" on the case.
Eventually the cousin lost contact with the four siblings as two of them were making their way back to their hotel. Later, the parents say they were told by their children that they had been taken by officials and brought back to Xinjiang, where they were interrogated and then sent to a Covid-19 quarantine center for two weeks.
When they were released, the four children were put into a state-sponsored orphanage.
In the county seat of Payzawat, about an hour's drive from Kashgar, CNN attempted to locate the four siblings with their parents' permission, but local officials did not allow the team to visit the children. CNN was able to connect with Yehya, the second-oldest child, over a WeChat video call, as what he called a "teacher" off camera prompted the young man with what to say to journalists.
When asked if he wanted to be reunited with his parents, he said, "I do."
At one point, a voice on the other end of the phone told Yehya, "Tell them that you see your sister every day." When asked if he wanted to pass on any messages to his parents, the voice told him to say that he had "nothing" to say to his parents.
Since their failed escape attempt, when the children occasionally gain access to a phone in the orphanage, they can speak to their parents. Recently, the children sent a photograph of the four of them standing in front of barbed wire outside the facility. Another image they sent showed the siblings with a sign in Chinese, saying, "Dad, Mom, we miss you."
Despite the difficulties they face in retrieving their children, Mihriban and Ablikim said they aren't going to stop trying.
Now living in the small Italian town of Priverno, near Rome, the couple encourage their three youngest children to kiss the photos of their older siblings every day.
"I will never give up until I bring back my children safely and rejoin with my family," Mihriban said.
In a report released in March, more than 50 global experts in international law and Xinjiang named China's removal of children from Uyghur families as a violation of the UN Genocide Convention.
Under the convention, "forcibly transferring children of (an ethnic) group to another group" is considered as an act of genocide, if it is intended to destroy the protected group. The experts found that was in the case in Xinjiang.
The March report quoted a Chinese government document that showed, between 2017 and 2019, the number of children who had been separated from their families in Xinjiang and placed into state-run boarding schools had increased by 76.9%, from just under 500,000 to 880,500.
During a news conference in Beijing on March 7, Chinese Foreign Minister Wang Yi denied there was any evidence of genocide occurring in Xinjiang, calling the allegations "preposterous."
Uyghur historian Rian Thum, a senior lecturer at the University of Manchester and co-author on the March report, said the placement of children in state-run orphanages is part of a Chinese government strategy to try to assimilate the Uyghur population.
"This is a consistent widespread policy, they have special terminology for it," Thum said. "We see it not just in one area or two, we can see it across the entirety of the Uyghur region."
The Chinese government has denied attempting to erase Uyghur culture, saying it respects all of China's ethnic minorities and religions. At a news conference in February, a spokesman for the Xinjiang government said there were a variety of reasons why Uyghurs overseas might have lost touch with their relatives back home, including that they may be "criminal suspects in police custody."
"If you cannot get in touch with your relatives in Xinjiang, you should contact the nearest Chinese embassy or consulate. We will work with them to provide assistance," he said.
But CNN's interviews with both sets of children illustrated the tight security and immense pressure under which many Uyghurs in Xinjiang -- both old and young -- live every day.
In his video call with CNN, Mihriban and Ablikim's son Yehya often repeated verbatim answers from the "teacher" next to him, glanced around nervously and looked off the camera.
Even when interviewed in their own home, Uyghurs appeared to watch their words. When Mamutjan's daughter Muhlise was asked during CNN's unannounced visit whether her mother had been sent to a "vocational training center," she whispered to her paternal grandparents who told her in Uyghur to "say nothing like that." "Say she is at home," her grandfather said.
The interview was cut short when the family said local authorities came around looking for them.
Mamutjan said he was worried not just about his own son and daughter but a whole generation of Uyghur children who had grown up under the crackdown in Xinjiang.
"The Uyghur children in the orphanages ... are being brainwashed, (they) would be clueless about their culture, about their language, and their religious values," he said.
For the four Ablikim siblings, their father is making a last-ditch, direct appeal to China's leader Xi Jinping, who has recently called his government's Xinjiang policy "completely correct," to allow the children to fly to Italy and reunite with their parents.
"President of China," Ablikim said. "I only want you to bring my children back."