Police in Beijing detained dozens of protesters from a group of hundreds gathered outside government buildings on Thursday in protest at a ban on migrant students sitting the all-important university entrance exam in the capital.
Around 70 parents of out-of-town high-schoolers were taken away by police after they gathered outside municipal government education offices, participants said.
"Eventually there were only six or seven of us left, and we were taken to a location where they gathered us together and took our personal details," said a parent surnamed Liang.
She Guowang, who acted as a representative for the group, said the detentions had begun late on Wednesday and continued into Thursday.
He said the protesters were held in a cafe until the police had noted their identities.
"It's mainly because of increased security ahead of the parliamentary sessions," She said. "They said that they understand that we want our voices to be heard at such a time of international importance."
"But now they won't let me go anywhere, although I can go online without limitations."
He said that only around half the parents who tried to protest had been taken back to police stations in the districts where they lived, while the rest were not detained.
"We are planning to go and visit them," She said.
Zhang Jiandang, a migrant worker now living in Beijing with a child of high-school age, said he was now being followed by police.
"They were waiting there for me in their car when I went downstairs," Zhang said. "I couldn't get out of the gate."
He said the parents were complaining that while some cities had eased restrictions on out-of-town children sitting university entrance exams, Beijing hadn't followed suit.
Beijing-based rights activist Xu Zhiyong, who has campaigned on behalf of migrant workers for equal access to education, said he had also been placed under surveillance since Tuesday.
"Equal education rights activism has been going on for around three years now," Xu said. "They have been making the same complaint every month, on a Thursday, for three years."
"Since the day before yesterday, I have been illegally detained at home," he said. "This probably has to do with the parliamentary sessions [in early March]."
Meanwhile, rights activist Wen Dao, who has also supported the campaign, said the parents had believed that access to education would be liberalized sooner or later.
"Now, they see that their hopes have been dashed," he said.
While the children of migrant workers will be allowed to sit college entrance exams in the eastern provinces of Anhui and Jiangsu, as well as northeastern Heilongjiang, if their parents work there, Beijing, Shanghai and Chongqing have much tighter rules.
A directive issued by the Beijing municipal government in November sparked an outcry, sending worried parents to petition the authorities in a bid to revoke the ban, which they say will jeopardize their children's futures.
Migrant workers who move to towns and cities to seek work in factories say they are often treated as unwelcome interlopers, and enjoy much less access to public services like education, welfare payments and health care than those who are registered as already living in the town.
Under the "hukou" registration system which dates back to the Mao era of collective farming and a planned economy, every household accesses services from its place of registration, posing huge social problems for China's hundreds of millions of migrant workers and their families.
China has nearly 20 million children aged under 14 who have followed their migrant-worker parents to cities, official media reported, citing figures from the China Children and Teenagers’ Fund.
The Chinese mainland’s 32 provincial-level authorities were required in August to submit plans on allowing migrants' children to sit the test away from their hometowns before the end of the year, Xinhua news agency reported.
Those not able to produce a Beijing "hukou" will be forced to return to the cities of their birth for the test.
Reported by Wen Yuqing for RFA's Cantonese service. Translated and written in English by Luisetta Mudie.