The protests, unprecedented in President Xi Jinping's decade in power, began in late November in cities across China. They were suppressed by police within days but helped hasten the end of three years of tough COVID restrictions, sources have previously told Reuters.
Immediately following the protests, in which hundreds took to the streets across the country, many holding up blank sheets of paper as a symbol of their discontent, police interrogated and detained dozens of participants, according to rights groups, lawyers and friends of those individuals.
Many were only held for 24 hours or less, or were released after a few weeks.
Cao Zhixin, a 26-year-old book editor, and Zhai Dengrui, a 27-year-old teacher, were released on Wednesday, according to two friends of the individuals.
Reuters could not immediately reach the pair for comment or establish why they were released.
The Ministry of Public Security and the Beijing Public Security Bureau did not immediately respond to a request for comment. They have not previously commented on the detentions.
Human Rights Watch had reported the pair were among four protesters detained in December and charged with "picking quarrels and provoking trouble", which carries a sentence of up to five years.
Cao, shortly before she was detained, had taken a video of herself calling for help. The clip was later released by friends and widely circulated online.
In it, she mentions that several of her friends who joined the protests were taken away by police.
Other protesters fell silent under the threat of official retribution but some have spoken out against China's crackdown on the largely peaceful demonstrations.
Reuters could not independently verify the total number of protesters who were detained by police or have been charged and remain in custody.
(Reporting by Laurie Chen; Editing by Robert Birsel)
By Laurie Chen
