Wikipedia has confirmed that all language versions of its online encyclopedia are now blocked to users behind China's Great Firewall.
"Access to Wikipedia has varied over the years with the Chinese language version being controlled more tightly than other versions," according to the Wikipedia page titled "Censorship of Wikipedia" said.
"As of April 2019, all versions of Wikipedia are blocked in China," it said.
The ruling Chinese Communist Party imposes tight control on what the country's 800 million internet users can do or see online, using a complex system of blocks, filters and human censorship known collectively as China's Great Firewall.
Chinese rights activist and tech expert Pu Fei said people had once relied heavily on versions of Wikipedia that were still accessible, to get access to uncensored information.
He said the new block is likely linked to a nationwide security clampdown ahead of the 30th anniversary of the Tiananmen massacre on June 4, 1989.
"This year, we have the 70th anniversary of Communist Party rule, their own anniversary, and the people's 30th anniversary [of the 1989 massacre], so you could say that things are pretty tightly controlled, especially the internet," Pu said.
China's own Baidu search engine runs an encyclopedia site, but content is strictly regulated by government censors.
Unified and preapproved thinking
Pu said there are contributors to Wikipedia who live behind the Great Firewall, yet were still able to contribute their knowledge and research to the site. He said many users would now lose access to uncensored content.
He called for an end to government censorship.
"I wish that the authorities would feel able to countenance the development of online activity with a more open mind," Pu said. "There should be no more interference. The internet should be a free space."
Current affairs commentator Jin Shan said it's also possible that Wikipedia has been blocked amid growing bilateral tensions and a trade war with the United States.
He said sites like Wikipedia pose a constant threat to the unified and preapproved thinking that the ruling party is trying to impose on its own officials.
"Once people are in the know, then they can't all hold the same views," Jin said. "Once that happens, this is going to have the effect of fragmenting decision-making."
"That's why they want a high degree of unity [among decision-makers], so that is one motivation [for the block]," he said.
Xia Ming, professor of political science at New York's City University, said the government is very nervous in the run-up to the sensitive anniversaries.
"Whenever they let things go a bit, there is more chaos [in public opinion], so then they tighten up control again as soon as that happens," Xia said. "This is how they have always done it."
Tightening under Xi Jinping
He said control of public speech and thought via the internet began to tighten across the board after President Xi Jinping took power in 2012, however.
"It's the only method known to Xi Jinping," Xia said. "They clearly believe that they can exert total control; it's their way of hanging onto power."
"Xi Jinping is facing a lot of popular resistance and various economic problems," Xia said. "He is also engaged in an internal power struggle within the party."
"Seen from this point of view, he is fighting for his life, especially because of the economic situation," he said.
Repeated calls to China's powerful Cyberspace Administration rang unanswered during office hours on Friday.
Wikipedia said the Chinese-language site had received positive coverage in the state media as late as 2004, but was then blocked on June 3 that year, ahead of the 15th anniversary of the 1989 Tiananmen Square protests and subsequent massacre by the People's Liberation Army (PLA).
In October 2006, The New York Times reported that English Wikipedia was unblocked in China, with the Chinese version unblocked the following month, sparking Wikipedia boom during which 300–400 new accounts were created daily and the rate of new registrations more than tripled to over 1,200 daily.
However, government censors began targeting specific articles at some point in 2006, Reuters reported, in particular the article on the June 4, 1989 massacre.
Forced amnesia on June 4
In 2012, both Chinese and English Wikipedias were accessible in China, with the exception of political articles.
Chinese authorities started blocking access to the secure (HTTPS) version of the site on 31 May 2013. However, the use of HTTPS meant that the government was unable to see which pages were being viewed by Chinese users, the article said.
"As a result, Beijing chose to block the whole Chinese Wikipedia; as of June 2015, both encrypted and un-encrypted Chinese-language Wikipedia are blocked," it said.
However, until last month, some Chinese users were still able to visit sites in other languages, including Japanese.
The 1989 protests, which took over Tiananmen Square for several weeks, were sparked by a spontaneous outpouring of public mourning following
the funeral of ousted liberal premier Hu Yaobang on April 22 that year.
The government styled the 1989 student-led democracy protests a "counterrevolutionary rebellion," and the families of victims and pro-democracy campaigners have since focused their efforts on a re-evaluation of that verdict, as well as demanding compensation and the apportioning of blame and responsibility for the massacre.
Public memorials and discussions of the events of June 1989 are banned in mainland China, with activists who seek to commemorate the bloodshed often detained, with veteran dissidents placed under police surveillance or detention during each anniversary.
Reported by Shi Shan for RFA's Mandarin Service, and by Wong Lok-to for the Cantonese Service. Translated and edited by Luisetta Mudie.