Twitter (TWTR) on Monday announced that it had suspended hundreds of accounts on its platform in connection with the protests roiling Hong Kong, citing a “significant state-backed information operation” sowing disinformation.

In a blog post, the social network said 936 accounts linked to China “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.”

In a separate move, Facebook (FB) announced hat it had removed seven public pages, three groups and five accounts that were behind “coordinated inauthentic behavior as part of a small network that originated inChina and focused on Hong Kong.”

Over 15,000 accounts followed one or more of the banned pages, while around 2,200 accounts joined at least one of the removed groups, Facebook stated.

Mass demonstrations have shaken Hong Kong — a semi-autonomous region of China — to its core, and reverberated around the world.

Weeks of continuous protests have escalated, sparking clashes between protesters and authorities and putting pressure on the Trump administration to support a freedom-seeking movement.

Twitter said that several of the banned accounts were using internet addresses that originated from within mainland China.

“Based on our intensive investigations, we have reliable evidence to support that this is a coordinated state-backed operation,” Twitter said. “Specifically, we identified large clusters of accounts behaving in a coordinated manner to amplify messages related to the Hong Kong protests.”

Among the accounts suspended by Twitter, some posed as news outlets in both Chinese and English. The users condemned violent actions taken by the protesters, citing media coverage from pro-Beijing newspapers Singtao Daily and Tai Kung Pao.

The accounts also claimed in tweets that Hong Kong’s legislative council was left in ruins after being attacked by protesters. In the example Facebook gave, one account posted images that compared protesters to ISIS.

The former British protectorate has now found itself caught in the middle of a geopolitical tug-of-war between the U.S. and China, which are sharply at odds over trade.

Last week, President Donald Trump explicitly called for Chinese President Xi Jinping to resolve the Hong Kong issue “quickly and humanely” — adding a new layer of tensions to a bilateral relationship that’s been strained to its limits.

“Should China’s security forces stage a large-scale intervention in Hong Kong, the linkage to trade would become direct,’ analysts at Eurasia Group noted recently.