Twitter has removed more than 170,000 accounts tied to a Beijing-backed influence operation that spread messages favourable to the Chinese government, including about the coronavirus.
The company suspended a core network of 23,750 highly active accounts, as well as a larger network of about 150,000 "amplifier" accounts used to boost the core accounts' content.
Twitter, along with researchers who analysed the accounts, said the network was largely an echo chamber of fake accounts without much further traction.
The company also removed two smaller state-backed operations, which it attributed to Russia and Turkey.
Twitter said the Chinese network had links to an earlier state-backed operation dismantled last year by Twitter, Facebook and Google's YouTube that had been pushing misleading narratives about political dynamics in Hong Kong.
The new operation likewise focused heavily on Hong Kong, but also promoted messages about the coronavirus pandemic, exiled Chinese billionaire Guo Wengui and Taiwan, the researchers said.
Renee DiResta, at the Stanford Internet Observatory, said the accounts praised China's response to the virus, while also using the pandemic to antagonise the United States and Hong Kong activists.
The US State Department said in May it had found a network of inauthentic Twitter accounts with "highly probable" linkages to China disseminating false coronavirus claims.
Twitter pushed back on the assertions at the time, saying the 5,000 accounts the agency identified included legitimate non-governmental organisations and journalists.
A Twitter spokeswoman on Thursday said the network it removed was not related to what the State Department had identified.
