As visitors flocked to view futuristic robots and experience virtual reality at a World Economic Forum exhibition in the northern Chinese city of Tianjin this week, hundreds of ordinary Chinese with grievances against the government have been flocking to the city in a bid to make their voices heard.
As visitors interacted with a showcase robot in the shape of an Asian woman with a demure expression and traditional dress, police were detaining large numbers of people outside the municipal government's complaints office, petitioners told RFA.
Security was tight, and police weren't allowing any petitioners to approach the building, petitioners at the scene said.
"There was a very large number of people outside the complaints department today, and the police were detaining them," petitioner Zhang Qiongxiu said.
"They were all lined up to make their complaints. There were more than 1,000 people there," she said.
"They and the interceptors were making them stand to one side, and then escorting them away," Zhang said, in a reference to officials from other places in China whose job it is to escort home anyone complaining about local government to a higher authority.
"I heard that several people were taken away yesterday too," Zhang said.
Top-level political meetings have long been a magnet for the vast number of Chinese people who pursue complaints against their local governments, often for years at a time and with scant hope of redress.
But petitioners increasingly face security checkpoints, body scanners and bag searches for documents, even as they seek to publicize official wrongdoing in the presence of global media.
Petitioners have reported beatings, harassment and illegal detention in "black jails" or "political re-education centers" after being taken home by interceptors, although some are released with a warning or forced to sign a pledge not to carry on with their complaint.
Zhang said detained petitioners were escorted onto buses, where their ID card details were recorded. They were then taken to an unofficial detention center in Tianjin, she said.
She said many more had been unable to leave home in the first place after being placed under surveillance by local authorities.
One man whose mother was among those detained said he is worried she will be locked up without trial in a black jail on her return home.
"They have already illegally detained my mother twice in a black jail, which they call a study center," he said. "Actually it's just an illegal jail, where no documentation is produced."
"The first time was for 17 days, and the second for 14 days," he said. "They lock people up in a room and give them a limited amount of food and drink, and sometimes they give them nothing to eat and drink for several days."
"They have abused my mother," he said.
China's army of petitioners files nearly 20,000 grievances in person every day to complaints offices across the country, according to official figures released in November 2013.
Faced with thousands of complaints about its officials every day, China has moved to ban its citizens from taking petitions directly to the central government without first going through local authorities.
The move has done little to curb the numbers complaining, however, often about the loss of farmland, forced eviction, official abuse of power and health problems linked to pollution.
Hebei petitioner Duan Shulan, who is seeking justice for 11 primary school students killed in an unreported school massacre in January 2005, said she has met with similar treatment and no response from officials.
"All the past 11 years of petitioning have got me is detention, death threats, kidnappings and surveillance," Duan said.
"The local police have even threatened to bury me alive."
Duan has been warned by authorities in her home city of Baoding not to petition in Beijing any more.
"But when you do come back here, they don't resolve the complaint for you," she said, adding that she has previously feared for her life, and has been largely protected by fellow petitioners.
Reported by Xin Lin for RFA's Mandarin Service, and by Wen Yuqing for the Cantonese Service. Translated and written in English by Luisetta Mudie.