Twenty people associated with a faith-based South African aid organization were taken into custody by Chinese officials last week during a tour of the country, Agence France-Presse reports.
Gift of the Givers said the 10 South Africans, nine Britons, and one Indian were detained upon arrival at an airport in China's Inner Mongolia region and that authorities are alleging ties to terrorism.
Eleven members of the party had been released as of Tuesday, but the others remain in detention "on the accusation that they were watching propaganda videos," Gift of the Givers said in a Facebook post.
The charity, which provides medical equipment and training in Asia and Africa, describes itself as inspired by Sufism, a mystical form of Islam. Chinese regulations ban foreigners from missionary activity, including "distributing religious propaganda materials." There has been no official word from Beijing about the reasons for the arrests, according to the BBC.