A prominent Chinese human rights lawyer and his wife have been arrested while traveling to the European Union embassy in Beijing, the EU said on Friday.

Yu Wensheng and his wife, Xu Yan, were detained on Thursday and whisked away in a police car to a police station “for going to an embassy,” Xu said in a video posted on her Twitter account.

In one of the clips, not accessible in China where Twitter is banned, Xu explained how they were forced into the car by “various people.”

The EU delegation in China said it lodged a complaint with China’s foreign ministry “against this unacceptable treatment.”

“We demand their immediate, unconditional release,” the EU embassy tweeted.

Yu was sentenced in 2020 to four years in prison for “inciting subversion of state power” and was released in March 2022.

Yu has a track record of high-profile human rights cases including the defense of Falun Gong practitioners, a banned religious group since 1999.

He represented people arrested in 2015 during the so-called 709-crackdown that saw Chinese authorities conduct a series of coordinated mass arrests across the country targeting human rights lawyers and activists.

The EU delegation also demanded the release of lawyers Wang Quanzhang, Wang Yu, and Bao Longjun, who are “under house arrest.”

Wang Yu was arrested in 2015 with over 300 human rights lawyers and activists during the 709-crackdown and was released on bail a year later. She has remained under the strict supervision of authorities ever since.

Wang Quanzhang remained in jail for five years until 2020 after being accused of “subversion against the state,” a charge commonly used against activists and dissidents.

Earlier this week, lawyers and activists Xu Zhiyong and Ding Jiaxi were sentenced to more than 10 years in prison after being found guilty of “subverting state power.”