Mahmoud Muhammad and his family were not home when Egyptian security forces knocked on the door of their flat in Cairo's Nasr City on June 30.

An hour later, security forces returned in full riot gear and forcefully entered the flat, sniffer dogs in tow. The Egyptian officers questioned other residents of the building about Muhammad, a member of Egypt's 700-strong Uighur community, as they attempted to determine his whereabouts.

Once he heard about the incident, Muhammad said, he immediately fled the country for Turkey and warned his family not to sleep in their flat any more. It had been 15 years since he first settled in Cairo to study at al-Azhar University.

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At least 30 Uighur students and residents were arrested on July 2 from their Cairo homes and restaurants that they frequented. Dozens more were detained in the ensuing days, all believed to be intended for deportation to China.

Sakhr al-Din Razi, a 22-year-old Uighur student who managed to evade arrest, told Al Jazeera that some of the detainees had been gathered inside the Tora maximum security prison on the outskirts of Cairo, awaiting deportation.

"They were split up in groups of 10 in various police stations, such as the Nuzha, Heliopolis and Ayn al-Shams branches," said Razi, who has gone into hiding since the wave of arrests. "Now they are in Tora, where communication has been completely cut off."

Speaking from Istanbul, Turkey, Muhammad told Al Jazeera that the exact number of arrests was unclear, as the Egyptian security apparatus had not released details.

"The detainees that are held in holding centres in the Cairo, Alexandria and Hurdaga airports are around 30, but there are probably at least 100 more that we don't know their location," he said. "Many of the students have disappeared; we don't know whether by choice or if the government is holding them in a secret location or police stations."

Human Rights Watch released a statement in the aftermath of the crackdown, calling on Egypt not to deport the Uighurs back to China where they, as a Muslim minority, could face jail or torture. A foreign ministry spokesman in Beijing acknowledged the detentions by saying that the individuals would receive consular visits, but gave no further details, according to a report from the Associated Press news agency.

Sarah Leah Whitson, a spokeswoman for Human Rights Watch, told Al Jazeera that Egypt acted upon China's request after two recent meetings between Egypt's interior minister and China's deputy public security minister, during which they discussed joint efforts to tackle "extremist organisations".

"Egypt is eager to build security relations with China, who is intent on intelligence-sharing and cooperation," Whitson said.

Xinjiang, an autonomous region northwest of China, is home to 22 million people, about 40 percent of whom are Uighur. The Turkic-speaking Muslim population has been persecuted by Chinese authorities for decades.

China regards Xinjiang, which translates as New Frontier, to be an important part of the country, rich in resources and bordering six other countries.

The Uighurs consider it as their traditional homeland and resent the influx of ethnic Han Chinese, who generally receive better jobs and salaries.

In recent years, the Chinese government has tightened its control over Xinjiang under the banner of combating "religious extremism", "terrorism" and "separatism". Uighur separatists have been subjected to forced disappearances, torture and execution.

In March, the government passed a law that listed 15 types of behaviour or commentary that it considered to be "extremism", including a ban on Muslim veils and "abnormal" beards.

Little information has been released about the fate of the Uighurs detained in Egypt. Whitson said that while she believes many have since been released, dozens remain unaccounted for.

"We don't know if they are held in Egyptian prisons or are at the Chinese embassy for further interrogation," she said.

Ismail al-Rashidy, an Egyptian human rights lawyer, said that some of the Uighurs were released after pressure from international organisations and campaigns.

"Twelve were deported in total," he told Al Jazeera. "There are no formal charges against those who are detained; otherwise, they would have been presented to the Egyptian courts. This is a case of arrest in preparation for their deportation back to China."

Rashidy, who found out about the arrests through social media, said the best move at this point was for the Uighur community to raise awareness to "pressure international human rights organisations into propagating their struggle".

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Egypt, as a signatory to the 1951 Refugee Convention, is obligated to not return foreign nationals to their home country if they face the risk of potential harm by their government.

However, other countries, such as Cambodia and Malaysia, have violated international law by forcibly returning Uighurs back to China. In August 2015, Thailand deported 220 Uighurs.

For Muhammad - who built a new life in Egypt, including the birth of all of his four children - the recent crackdown by Egyptian authorities came as a shock. He said there was widespread fear in the Uighur community as security forces continued to pursue those who were not arrested in the initial sweep. Many were also afraid of travelling outside of the country because they could be stopped or detained, prompting some to disappear from public view.

"I never broke any law and was never stopped by police or interrogated by authorities," Muhammad said. "We know that the Egyptian people are not in support of what is happening to us and stand with us.

"Here in Istanbul, I was welcomed by the Uighur community," he added. "But my children and I miss Egypt, our home, and our life there."