BEIJING (Reuters) - A U.S.-based online publishing platform, Medium, has been blocked in China, the company said, the latest service to be affected as Beijing exerts greater control over the Internet.
Medium, which allows users, including companies and media outlets, to post blogs that readers can annotate, has been inaccessible since at least early this week, according to Internet users in China and tests by Reuters using tools developed by anti-censorship watchdog GreatFire.org.
A representative of San Francisco-based Medium said in an email: "We are aware of the block and we don't have definitive knowledge why the block has occurred."
China's Internet regulator did not respond to a faxed request for comment.
Last week, a Medium post about the Panama Papers leak, detailing the offshore wealth of various countries' leaders and their relatives, including China's, was widely shared on Chinese social media.
China has moved to limit access to coverage of the matter and has censored online reports about it.
Also last week, Medium said more than a dozen media outlets would start publishing on its site, an arrangement that would have allowed publications whose websites are blocked in China to reach users in the country.
Medium joins a range of sites already blocked in China, including the blogging platforms WordPress and Google's Blogger.
The websites of several major media outlets are also blocked, including those of the Economist and Time, which both become inaccessible last week after they ran articles critical of President Xi Jinping.
Under Xi, the government has tightened control on the Internet and sought to codify that policy in the law.
Officials say Internet restrictions are needed to ensure security in the face of rising threats, such as terrorism.
Foreign governments and business groups have pointed to restrictions on the Internet as a broader trade issue.
On Friday, a U.S. business lobby said Internet restrictions were hampering business and that the free flow of information was critical to China's effort to promote innovation.
(Reporting by Paul Carsten; Additional reporting by Michael Martina, Beijing Newsroom and Jonathan Weber in San Francisco; Editing by Robert Birsel and Grant McCool)