Bishop Peter Shao of Wenzhou has been taken to an unknown location amid pressure for him to join a state-sponsored body in charge of Chinese Catholics.
The protest comes as a U.S. congressional report hits out at a string of recent blows to the city's traditional freedoms of speech, association and publication.
Democratic politicians and journalists say Beijing's 'red lines' are vague and subject to change, and that the city's government nods along with them too willingly.
At least one student is detained after a protest outside the Apple Store in Beijing, while student Marxists in Nanjing are beaten by 'unidentified men.'