A group of 37 Chinese and Taiwanese nationals who were cleared of criminal charges in Kenya were deported to China in hoods, to face prosecution on the same charges there.

The 37 men, part of a larger group that was charged with cybercrime by a Nairobi court last year, was acquitted last week in Kenya. But instead of being released, they were suddenly deported to China, a move that Taiwan officials call an “uncivilized act of extrajudicial abduction.”

The men were photographed arriving in China in handcuffs, with hoods over their heads today (April 13).

China’s Ministry of Public Security released a statement today saying that this “criminal syndicate” had cheated Chinese people out of millions of yuan across nine provinces, causing businesses to go bankrupt and people to commit suicide. Because their victims are in China, they will be prosecuted in China, the security bureau said, according to the state news agency Xinhua (link in Chinese).

China considers Taiwan a province, while Taiwan operates as an independent country, with democratic elections and no formal sworn allegiance to leaders in Beijing.

The incident threatens to become one of the worst diplomatic spats between Taiwan and China in years. Taiwan claims that Beijing kidnapped their citizens, and pressured Kenyan authorities to defy court orders and break the law. Kenyan police used tear gas and assault rifles to force the Taiwanese in the group to board a plane bound for China rather than Taiwan, officials say, breaking a cross-strait agreement in place since 2011 not to extradite each others citizens.

China’s public security bureau justified the decision to bring the Taiwanese to China by saying previous suspects in Taiwan had gone free.

“Because of the separate handling of these cases, many suspects of cybercrime in Taiwan have not received the proper punishment and stolen funds have not been able to be returned to China,” the agency said in a statement. Taiwanese officials have been invited to China to help with the investigation, according to the bureau.

Another group of 41 Taiwanese and Chinese nationals arrested last week on suspicion of similar charges has also been deported for a trial in China. Kenya has always recognized Beijing as the government of China. While 22 other African countries established diplomatic relations with the Republic of China in Taiwan, Kenya has always only recognized Taiwan.

Another 40 people, including five Taiwanese, remain in Kenya awaiting trial. “It’s hard to anticipate what will happen,” John Chen, the head of the Taipei Liaison Office in South Africa, tells Quartz. “It depends on whether China will continue using these illegal methods. China and Kenya are so close that whatever China wants to do, it probably can.”

Taiwanese officials have used a bilateral hotline to call on China to rein in its actions. ”We are using this hotline to call on them not to do this again. We need them to take that message in. We’ll see whether or not it works,” Chen says. They have spoken to Kenyan police and accused the country of becoming an “accomplice” to Beijing’s illegal actions.

China is showing its dominance of Taiwan in Africa just as Taiwan’s new president Tsai Ing-wen, from the political party that favors independence, prepares to take office. It is pushing Taiwan further from China, some say. Chen says, “They want Tsai to have a more pro- China position, but now that the Taiwanese public is even more repulsed by China, how can she be more pro-China?”