Authorities in the southwestern province of Sichuan have detained seven petitioners protesting forced eviction from their homes, rights activists said.
The petitioners were among a group of 300 textile workers who staged a protest outside the Sichuan provincial government buildings in Chengdu on Wednesday in protest at their eviction and welfare payments.
They were detained after being invited for talks with government officials on Thursday, activists said.
"We went yesterday, those of us who were evicted along with some of the retired workers," said petitioner Wang Yan.
She said officials had told the petitioners that they should go to the district government office the following day for a meeting with local officials.
But after the meeting had ended, police detained seven people, including petitioners Li Ying and Gao Zhiming, Wang said.
"The police suddenly detained seven people," she said. "There were three women and four men, and five of them were representatives who'd been at the talks."
She added: "The three women were all evictees."
Sichuan-based rights activist Huang Qi, who founded the 64Tianwang website, said a former military clothing and bedding factory had recently carried out a series of illegal evictions and demolitions at its worker accommodation sites.
"There were clashes with the workers, and some of the residents were injured," Huang said. "This is why they were all going to the provincial government."
"Some have even been as far as government departments in Beijing to complain about it," he said.
"They haven't had any sort of resolution at all, however," Huang said.
He called on the local authorities to respond to the petitioners' complaints.
"It shows a positive attitude that the government sat down to talk to the victims about [this]," Huang said.
Elsewhere in Sichuan, authorities in Zigong city stepped up their surveillance of political activist Liu Zhengyou, who was released this year from labor camp after being sentenced on "fraud" charges.
Liu had been active for many years in and around Zigong city, frequently helping farmers who had lost their land to government-backed property developers to sue for fair compensation.
Now designated a "sensitive person," Liu said he had received a warning from police that he should continue to report his whereabouts to the police station for the next five years.
"They said it was on the orders of the public security ministry, but they didn't give me a document to prove it," Liu said. "I'm extremely angry about this."
"I told them I was a citizen, and asked them on what basis they thought they could do this."
Ordinary Chinese with grievances against the government frequently complain of being held in unofficial detention centers, known as "black jails," if they protest against alleged wrongdoing by local governments.
Petitioners also frequently report cases of beatings, kidnappings, and "accidental" deaths which befall them as they seek redress through the ruling Communist Party's complaints system.
Reported by Qiao Long for RFA's Mandarin service. Translated and written in English by Luisetta Mudie.