Authorities in the northern Chinese city of Xi'an are holding two activists who tried to launch a street protest over the toxic smog that routinely blankets the country, fellow protesters said Monday, as censors removed all access to an environmental documentary from local websites after it went viral on the country's tightly controlled Internet.
A fellow protester from Xi'an, who gave only his online nickname "Zhanpo Dao," said Zhang Hui and Feng Honglian, known online as "Wu Mian," were in a police-run detention center, suggesting the authorities plan to bring criminal charges against them.
"They have both been visited in there by others, and their stuff has already been transferred over there," Zhanpo Dao told RFA on Monday. "Some people took them some food and water and other things."
He said it was unclear what the police planned to do next.
"There hasn't been any sort of official paperwork, so right know it's hard to say whether they are being criminally detained or held for interrogation," he said.
"But they have definitely lost their freedom."
Zhanpo Dao said the detentions had come as more than 20 people took to the streets of Xi'an on Sunday, holding up placards in protest at a lack of government action over air pollution.
"The smog should be dealt with by the government, but the government isn't doing its job," he said. "So we have no other option but to come out onto the streets."
"We held up banners and placards in the hope of forcing the government to do something about the smog," he said. "We never thought they'd ... detain people."
"All we wanted was for other people to see us, and to understand this cancer [of corruption], how it came about, so the government would act."
Xi'an-based lawyer Dong Falin said he planned to represent Zhang and Feng, who had done nothing illegal.
"It is an abuse of official power for the police to detain someone for this long simply for expressing their demands in a normal manner," Dong told RFA on Monday.
"This was just an expression of their opinions."
'Under the Dome'
China recently censored "Under the Dome," a hard-hitting documentary film looking at the causes of the country's "airpocalypse" smog problem, taking it down from video-sharing sites after it clocked up more than 150 million online views.
A link to the film on the Chinese video site Youku returned the message: "We apologize, but Youku couldn't find the page you requested."
Former China Central Television (CCTV) anchor Chai Jing released the self-funded film online earlier this month.
Chai said she was driven to make the 104-minute feature-length documentary, which is in the style of a public talk, after her baby daughter was born with a lung disease.
The film, which has been dubbed China's "Silent Spring" or "Inconvenient Truth," details the causes of smog in the country, including slack government supervision and lenient penalties for polluters.
While highly politically sensitive, the film had originally been released in partnership with official media and praised by environmental protection minister Chen Jining.
Last week, President Xi Jinping told delegates to the National People's Congress (NPC) that polluters would be punished "with an iron hand."
"We are going to punish, with an iron hand, any violators who destroy ecology or the environment, with no exceptions," Xi said shortly before the film was censored.
Campaigners say that China has an exemplary set of environmental protection legislation, but that close ties between industry and officials mean that it is rarely enforced at a local level.
Worsening levels of air and water pollution, as well as disputes over the effects of heavy metals from mining and industry, have forced ordinary Chinese to become increasingly involved in environmental protection and protest.
Many have been prompted into action by China's environmental crisis, sparking a rise in "mass incidents" linked to pollution, while environmental groups have raised growing concerns over the falsification of pollution testing and environmental impact assessments.
Rights lawyer Tang Jitian said Zhang and Feng's detentions showed that China's ruling Communist Party sees any sort of citizen protest as a threat, however.
"The government sees the exercise of power by its citizens as a threat to its authority, and to its existence," Tang said.
"That's why they won't let any [activist] slip through the net."
PX plant
Last week, authorities in the southwestern province of Sichuan detained around 10 environmental activists linked to a protest against alleged pollution at a petrochemical plant in Pengzhou.
Organizer and rights activist Chen Yunfei said the protest came amid complaints of heavy pollution from production of paraxylene, or PX, at the plant.
Chen and a group of fellow activists were "forcibly dragged" to the local police station after they gathered outside the plant on March 6, he said.
"This was a normal activity that wasn't on the factory premises," he said. "There was nothing to incite people, or that broke any law or rules, on our banners."
Sichuan-based rights activist Huang Xiaomin said Sichuan was once regarded as somewhere with a relatively clean environment.
"Now, it is the third most polluted place in China," Huang said. "This shows that [the PX plant] is contributing in no small amount to environmental destruction."
Chinese authorities have tried to locate PX facilities in a number of major Chinese cities in recent years, including Dalian and Xiamen, only to meet with vocal public opposition each time.
In April 2014, thousands of protesters converged on government buildings in the southern province of Guangdong during several days of protests against plans to locate a 3.5 billion yuan (U.S. $563 million) PX plant in densely populated Maoming city.
And in May 2013, government plans to produce PX at a petrochemical plant in Anning city, near the provincial capital of Yunnan in southwestern China, brought large crowds onto the streets in protest.
Reported by Yang Fan for RFA's Mandarin Service, and by Wen Yuqing for the Cantonese Service. Translated and written in English by Luisetta Mudie.