Zoom Video Communications Inc. said it deactivated accounts of pro-democracy Chinese activists based in the U.S. at the request of China’s government, renewing concerns about the software-maker’s ties to the communist country.

Beijing officials reached out to Zoom in May and early June about four videoconference calls that were publicized on social media to commemorate Tiananmen Square protests, the San Jose, California-based company said Thursday in a blog post. Zoom said that China "demanded” the company terminate the meetings and host accounts because of the activity, which it deemed illegal.

Zoom said that at least three of the four meetings contained participants from mainland China, and it made the decision to end three of the meetings and terminate the associated accounts, two in the U.S. and one belonging to an activist in Hong Kong.