Authorities in Beijing are holding a group of activists under house arrest and administrative detention after they tried to register as independent candidates in district legislative elections, which are usually controlled by the ruling Communist Party.
"All 13 of us independent candidates are now under guard," said Han Ying, who applied to stand for elections to the local tier of her National People's Congress (NPC) ahead of a November poll.
"There are strict orders not to allow any of them to come to my home," said Han, who had planned to launch her election campaign on Friday morning.
The attempt to field ordinary citizens to run against Party-backed candidates, who are not used to serious political opposition, has spread across China, with activists coordinating their attempts online, campaigning on each other's behalf, and trading advice and tips.
"There are a lot of plainclothes officers near my house, and the police come to my home every day to stop me from campaigning and to stop me from meeting with journalists," said Han, from a basement room in another apartment building where she was being held.
She said the police had set crowd barriers some distance from her home and were not allowing journalists to go beyond them.
"If I try to make a phone call they snatch away my cell phone," Han said.
"There were about seven or eight uniformed police and a lot more plainclothes police, and a lot of people from the neighborhood committee," she said.
'Explaining' the rules
Han said she was being held in a small room along with some police officers and some of her local neighborhood committee, who were trying to "explain" the election rules to her.
"I told them I understood the rules, but they insisted on telling me all over again," Han said.
"I told them they didn't have the right to curb my freedom, nor to confiscate my cell phone. They haven't let me go home yet," she said.
An employee who answered the phone at the Wanshousi police station declined to comment.
"We don't really know the situation," the employee said. "You need to ask the Haidian district police station's propaganda department."
A second independent candidate, Ye Qingchun, confirmed there was a strong police presence outside Han's home. She said she was also being held by police at her home in Beijing's Xicheng district.
"This morning I went to the gates of Han Ying's [apartment complex] after a very fierce argument," said Ye, whose police minders eventually agreed to take her there in their car.
"We took a turn near the gates and saw the situation there," she said. "I sat there in the police car but there was no way I was going to be allowed to get out," she said.
Police block entrance
Ye said she saw a large crowd of people at the gate of Han's apartment complex, and at least two police vehicles, as well as a group of people including police at the entrance to the building.
Han said the police intended to prevent her from campaigning in the NPC elections, which take place on Nov. 8 in the capital.
"Their main purpose is to stop me campaigning," she said. "I told them that I was operating within the framework of the law, and that I hadn't broken the law in any way."
Three other candidates had been detained by police on Thursday, fellow campaigners said.
Among them was Wu Lihong, who had been given 15 days' administrative detention by the Chaoyang district court, according to her friend, Wei Hongmei.
"Three people: Wu Lihong, Qi Yueying, and Li Shanlin were all detained," Wei said. "The [other two] were originally Wu Lihong's representatives, arguing her case with the court."
"I don't know why, but they all ended up getting 15 days' detention for obstructing public servants in the course of their duties."
He Depu, a former member of the banned opposition China Democracy Party (CDP) who stood as a candidate for provincial elections in 1980 and 1998, said the detentions were directly linked to Wu's attempt to run for her district-level NPC.
"This definitely has to do with her NPC election candidacy," said He, who was himself briefly detained by police last week after he tried to help the 13 Beijing-based candidates with their campaign.
"This is a terrible blow to Wu Lihong, because she will no longer be able to campaign as an NPC candidate for that whole time."
'Getting it wrong'
He said the authorities appeared to be gaining confidence in dealing with independent election bids.
"They are getting this badly wrong, because in the end they will lose public trust," he added.
Dozens of political activists across China have joined the campaign to file applications to stand for the elections, in spite of official warnings that there is "no such thing" as an independent candidate.
Official media have said that anyone hoping to stand for elections this year to the district-level congresses will first have to clear "due legal procedures," the official Xinhua news agency reported.
However, activists are hoping to use a clause in the election rules which allows anyone with the endorsement of at least 10 constituents to seek nomination.
Some of the candidates come from the least privileged groups in society, including those who have been forcibly evicted from their homes, or who have long campaigned for their legal rights.
Apart from a token group of "democratic parties" which never oppose or criticize the ruling Communist Party, opposition political parties are banned in China, and those who set them up are frequently handed lengthy jail terms.
More than two million lawmakers at the county and township levels will be elected during nationwide elections, held every five years, in more than 2,000 counties and 30,000 townships from May 7 through December of next year.
Reported by Qiao Long for RFA's Mandarin service. Translated and written in English by Luisetta Mudie.