A rights and citizen journalism website based in the southwestern Chinese province of Sichuan said its operations have been paralyzed by a hacker attack on Tuesday, while a second site said its domain name is once more blocked on China's tightly controlled Internet.
Activist Huang Qi, who founded the Tianwang website, said the home page and articles were unaffected by the attack by unknown hackers.
"But we can't get into the interface for contributors to post copy, which means that we have no way to post articles to the website," Huang said.
He said the group had taken to posting articles on social media platforms Google+ and Facebook, which are blocked to the majority of users inside China, and the group's blog.
"We have been unable to post articles since around 10 a.m.," Huang said. "The registration page is also broken. I think it's been attacked."
Tianwang, which started out as a resource for relatives of those killed or injured in the military crackdown on the 1989 pro-democracy movement, soon changed its focus to cover ordinary Chinese who seek to defend their rights in the face of official abuses of power.
It often posts the stories that rarely find expression in China's tightly controlled, state-run media, and that are often deleted from social media sites soon after they appear.
Currently, at least four of its citizen journalists are in detention amid an ever-widening crackdown on freedom of expression and nongovernmental groups in the country, the Paris-based press freedom group Reporters Sans Frontieres (RSF) said in a recent report.
"Tianwang has a lot of articles, many of them about folk heroes like retired military officers and farmers who have lost their land," Huang said.
"Tianwang has a lot of news about farmers standing up for their rights, and also about ordinary citizens who get detained, including details of their trials and issues like torture and mistreatment in prison," he said.
"I think that is the reason it has been attacked."
Huang said the cyberattack was likely the 20th since the beginning of the year.
"It causes a lot of problems for our work," he said.
Rights website shut down
Meanwhile, rights website Watchdog Net for Citizens and Public Opinion was shut down in recent days, founder Li Xinde told RFA.
"Our registration number has been canceled [for the Chinese hosted site], and our ... domain name from our server in the United States has been blocked," Li said.
"Everyone knows our website's main theme is anti-corruption, and another big theme is rights activism."
Li said it wasn't hard to imagine the motivation for falling foul of the complex system of blocks, filters and human censorship known collectively as the Great Firewall.
"When we are overseeing government, there is nowhere we won't go; it doesn't matter who you are [as an official]; if you are corrupt, we will expose you," he said.
"So of course we are going to cause a reaction among some people, to stir up feelings among some people in power," Li said, adding that the site has already changed domain names 50-60 times this year.
The attacks on the rights websites come as Beijing rolls out a slew of draconian new laws aimed at further clamping down on freedom of expression online.
China's parliament, the National People's Congress (NPC), last month set out proposals to extend Beijing's already tight grip on the Chinese Internet in a draft cybersecurity law.
The draft law aims to "ensure network security, [and] safeguard the sovereignty of cyberspace and national security," according to the NPC’s official website, and will ensure Chinese Internet users aren’t allowed to "disturb the social order, [and] harm the public interest."
Meanwhile, tough new regulations requiring online publishers to attend "chats" with officials and police if they post content deemed false or inappropriate suggest a strong-armed role for China's new Internet regulator, the Cyberspace Administration.
The agency last month set out a serious of violations of rules on web content that could prompt a summons to "drink tea," a technique traditionally employed by the state security police to warn, interrogate and intimidate rights activists and dissidents.
Sites deemed to have published banned content—which might include "false information, pornography and rumors" will be obliged to send a representative to such meetings from June 1, according to official media.
Reported by Qiao Long for RFA's Mandarin Service. Translated and written in English by Luisetta Mudie.