China has deported a group 20 foreign tourists from Britain, South Africa and India for watching video clips that allegedly advocated terrorism and religious extremism, the official state media reported.

China has deported a group 20 foreign tourists from Britain, South Africa and India for watching video clips that allegedly advocated terrorism and religious extremism, the official state media reported.

At least two of the tourists, however, said they were actually just watching a documentary about the 13th century Mongol leader Genghis Khan.

Xinhua news agency said late on Saturday that the foreigners watched an unspecified documentary in a hotel room and later some of them watched video clips that advocated terrorism in the border region of Inner Mongolia. The foreigners said it was a misunderstanding.

The news agency cited the foreign affairs office of Ordos city, where police had stopped the 10 South Africans, 9 Britons and one Indian on July 10 as they were going to fly to Xi'an, home of the ancient terracotta warriors sculptures and their next stop on a 47-day tour of the country.

Britain's Press Association reported that the documentary was a BBC production on Genghis Khan, citing a statement from two of the British tourists, husband and wife Hoosain and Tahira Jacobs. They said that the video "may have mistakenly been deemed as propaganda material".

"It can only be assumed that junior officials who made the initial arrest in Inner Mongolia made a mistake, due to perhaps their unfamiliarity of the English language," the statement said.

The Jacobs also said that the group was a mixture of Muslims, Christians and Hindus who had travelled together in the past, including to Israel and the United States. They had visited the Genghis Khan Mausoleum in Ordos the day before they were stopped at the airport.

Xinhua said that the foreigners were criminally detained on July 11 in connection with a law that "stipulates punishment for allegedly organising, leading or joining terrorist groups".

It said the nine "admitted to their legal acts and repented," without elaborating. It said police treated the case leniently and deported them on Saturday.

The other 11 were deported on Wednesday.

Calls to the foreign affairs office in Ordos by the AP news agency rang unanswered Sunday. A man on duty at Ordos police, who only identified his surname, Han, said he had no information on the case.