Twitter on Thursday said it removed more than 170,000 China-linked accounts involved in range of “manipulative and coordinated activities,” including some 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 is blocked in China. The company also removed two smaller state-backed operations which it attributed to Russia and Turkey.