Chinese authorities will release 11 South African and British tourists held since July 10 on suspicion of having ties to terror groups, according to an aid organization familiar with the case.

Nine more tourists, however, remain in a jail in China’s remote Inner Mongolia region, after being arrested at the airport in the city of Ordos last week on “suspicions of criminal wrongdoing.”

The detained are accused of being “linked to a terror group [and of] watching propaganda videos in their hotel room,” according to the South African charity Gift of the Givers, which has been monitoring the situation.

Several of the tourists were Muslim, according to the charity, raising suspicions that their arrest may be linked to a broader Chinese crackdown against Muslim Uighur's in China's far-west Xinjiang Province. Many Uighurs, a Turkic ethnic group that is about 40 percent of the population in the province, oppose what they see as Beijing's slow cultural and economic takeover of their traditional region.

A spokesperson for the charity said the arrests were a mistake and that the tourists were probably watching a video of a gathering for Ramadan, the Islamic holy month now underway. Gift of the Givers is a a faith-based group that comes out of the Sufi Muslim tradition.

The arrests come as South Africa's deputy president Cyril Ramaphosa is on a five-day trip through China, prompting calls for him to intervene directly.

“It is inconceivable that a government hosts another government on a state visit and simultaneously incarcerates 10 of its citizens without charge,” Gift of the Givers wrote on its Facebook page Wednesday. "The Chinese must be told in no uncertain terms to provide the evidence and proof if the South Africans have terror links, charge them and take them to trial, alternatively, they must release them immediately and unconditionally.”

China crackdown on the Uighurs has received considerable criticism, The Guardian reports.

“The officially atheist Communist party has faced international condemnation for its hardline treatment of Muslim communities in the far western region of Xinjiang. Under-18s are banned from entering mosques and there are regular reports of local authorities banning Muslims from fasting during Ramadan.

A “people’s war on terror” was launched in the region in May last year after a spate of deadly attacks that Beijing blamed on Islamic extremists. This week there were reports that Chinese police in the north-east had shot three suspected terrorists from Xinjiang.

Some South African media suggest the arrests may be a result of the membership that some of the South Africans’ have with the Gift of the Givers. The Mail & Guardian, a South African newspaper, reports that, “Chinese regulations passed in 2000 ban foreigners from all missionary activity including “distributing religious propaganda materials.”

Gift of the Givers has an extensive history of providing aid across the developing world, and has previously been involved in negotiations for the release of hostages, including Pierre Korkie, a South African schoolteacher being held by al-Qaida in Yemen who was killed during a rescue effort by US Special Forces last year.

The all-powerful Chinese Communist party, suspicious of overseas groups, has in recent months tightened controls on foreign charities working in the country.

The tour group, which was 30 days into a 47-day tour of ancient Chinese sites, included 10 South Africans, nine Britons, and one Indian, the Associated Press reports.

Among the arrested were three family members of a prominent local business leader, Shameel Joosub, CEO of Vodacom, a South African subsidiary of a British telecom company, according to the Wall Street Journal.

“My family and I are deeply concerned for the safety and well-being of my brother, aunt and uncle,” Mr. Joosub said in an emailed statement to the WSJ. “We are in close contact the South African authorities who are working to secure their release.”

The Chinese Foreign Ministry told The Guardian that the case was “being handled in accordance of law.”

Get the Monitor Stories you care about delivered to your inbox. By signing up, you agree to our Privacy Policy

“China will protect relevant people’s legal rights in accordance with the law and will continue providing the necessary assistance and convenience to relevant embassies for their consular duties.”

China is attempting to deepen its diplomatic bond with South Africa and India — two of the countries from which the arrested are citizens — following a summit of the BRICS countries in Russia earlier this month.