People gather Sunday in Lafayette Square in front of the White House in solidarity with the “Stand With Hong Kong, Power to the People Rally” in Hong Kong. Carolyn Kaster/Associated Press

Twitter said Monday it was suspending nearly a thousand Chinese accounts and banning advertising from state-owned media companies, citing a “significant state-backed information operation” related to protests in Hong Kong.

The accounts were part of a larger network of roughly 200,000 accounts that were proactively deleted before they were substantially active, Twitter said in a blog. That’s despite Twitter being blocked in China, the company added.

“Overall, these accounts were deliberately and specifically attempting to sow political discord in Hong Kong, including undermining the legitimacy and political positions of the protest movement on the ground,” Twitter said. “Based on our intensive investigations, we have reliable evidence to support that this is a coordinated state-backed operation.”

The company said in its blog post that state-backed news media accounts “will be free to continue to use Twitter to engage in public conversation,” just not its advertising products.

Separately, Facebook said Monday it was removing five Facebook accounts, seven pages and three groups after being tipped off by Twitter. This is the first time the company has taken action against China for coordinated inauthentic behavior. Though Facebook is not considering a ban against advertising from state-sponsored media, they say they are working on additional transparency measures.

Twitter said that the accounts it suspended were accessed from VPNs or unblocked IP addresses originating from China.

This is the first time the company has disclosed information operations with ties to China. Twitter said that the new advertising policy was something that had been discussed internally for some time.

Hundreds of thousands of protesters have been demonstrating for an autonomous Hong Kong over the past two months, including a peaceful march Sunday. Hong Kong police have deployed unprecedented force, including in residential neighborhoods, and made more than 700 arrests to discourage further unrest. Protesters and pro-establishment groups have clashed violently. And Beijing has ramped up pressure.

Twitter confronted the same issue in 2016 after discovering that Russia Today, which the U.S. government has labeled a propaganda arm of the Kremlin, had purchased roughly $1.9 million in ads over an eight-year period.

The new slate of takedowns by Facebook and Twitter reflect the extent to which disinformation has become a global scourge, far surpassing the once-secret efforts of Russian agents to stoke social unrest in the United States during the 2016 presidential election. Researchers recently have pointed to similar campaigns linked to Saudi Arabia, Israel, China, the United Arab Emirates and Venezuela, each of which has tried to shape discussions on social media beyond their borders.

Some of this activity has come under the auspices of state-controlled media. In August, for example, Facebook, Google and Twitter each identified a sprawling disinformation campaign originating out of Iran, which posted content – and in some cases, purchased ads – in a bid to amplify accounts with ties to state news organizations.

Google did not immediately respond to a request for comment.

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