MELBOURNE, Australia — China has cracked down on the discussion of military affairs within its so-called Great Firewall, potentially limiting open-source coverage of the country’s defense developments.

Several accounts that covered Chinese military affairs on the local a social media application Sina Weibo, which is similar to Twitter, were recently suspended. In addition, forums on the Chinese website that discussed developments in the People’s Liberation Army were also closed by the site’s administrators.

These actions come in the wake of a Weibo account run by the military’s official newspaper, the PLA Daily, posting a commentary warning China’s military enthusiasts to avoid being unwitting tools for foreign intelligence services.

The Weibo account, Jun Zhengping Studio, which roughly translates to “Military Discussion Studio,” cited a recent incident where a photo published on social media showed “a weapon that has yet to enter service,” which became “key intelligence” for foreign agencies seeking information on China’s defense and military developments.

It added that this incident was the latest in a string of similar occurrences and warned that even unwitting revelations of military secrets by defense enthusiasts who are otherwise supporters of a strong Chinese military could potentially lead to prison terms.

It’s unclear what recent revelation the commentary was referring to; although in recent months, video of a Xi’an H-6N bomber carrying what is believed to be an air-launched hypersonic glide vehicle as well as photos taken discreetly from a distance showing elements of the internal layout of China’s third aircraft carrier currently undergoing construction at a shipyard near Shanghai first appeared on China’s social media.

The crackdown is potentially detrimental to those who use open-source material to analyze China’s military developments. Other examples of such sources include a regular stream of photos showing the progress of the aforementioned aircraft carrier undergoing construction at Changxing island near Shanghai, sometimes taken by passengers on commercial airliners taking off from or landing at the city’s Pudong airport.

Other open-source material includes images acquired through commercial satellite imagery, which help counter the secretive state of China or sometimes misleading information put out by state-controlled media.

Mike Yeo is the Asia correspondent for Defense News.

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