A young Chinese woman says she was held for eight days at a Chinese-run secret detention facility in Dubai along with at least two Uyghurs, in what may be the first evidence that China is operating a so-called “black site” beyond its borders.

The woman, 26-year-old Wu Huan, was on the run to avoid extradition back to China because her fiancé was considered a Chinese dissident. Wu said she was abducted from a hotel in Dubai and detained by Chinese officials at a villa converted into a jail, where she saw or heard two other prisoners, both Uyghurs.

She was questioned and threatened in Chinese and forced to sign legal documents incriminating her fiancé for harassing her, she said. She was finally released on June 8 and is now seeking asylum in the Netherlands.

While “black sites” are common in China, Wu’s account is the only testimony known to experts that Beijing has set one up in another country. Such a site would reflect how China is increasingly using its international clout to detain or bring back citizens it wants from overseas, whether they are dissidents, corruption suspects or ethnic minorities like the Uyghurs.

Wu, however,  could not pinpoint the exact location of the black site. However, reporters have seen and heard corroborating evidence including stamps in her passport, a phone recording of a Chinese official asking her questions, and text messages that she sent from jail to a pastor helping the couple.

China did not respond to multiple requests for comment sent to the Ministry of Foreign Affairs and its consulate in Dubai. Dubai also did not respond to multiple phone calls and requests for comment to the Dubai police, the Dubai Media Office and the UAE Ministry of Foreign Affairs and International Cooperation.

Black sites are clandestine jails where prisoners generally are not charged with a crime and have no legal recourse, with no bail or court order. Many in China are used to stop petitioners with grievances against local governments, and they often take the form of rooms in hotels or guesthouses.

The Uyghur Human Rights Project tracked 89 Uyghurs detained or deported from nine countries from 1997 to 2007 through public reports. That number steadily increased to reach 1,327 from 20 countries from 2014 until now, the group found.

Besides the UAE, many other countries have cooperated with China in sending Uyghurs back. In 2015, Thailand repatriated over 100 Uyghurs to China. In 2017, Egyptian police detained hundreds of Uyghur students and residents and sent them back as well.

The Uyghurs are recognized as native to the Xinjiang Uyghur Autonomous Region in Northwest China. They are considered to be one of China’s 55 officially recognized ethnic minorities. The Uyghurs are recognized by the Chinese government as a regional minority and the titular people of Xinjiang.