Teleconferencing company Zoom admitted that it closed down the accounts of activists as well as online ceremonies commemorating the Tiananmen Square massacre at China’s request. The revelation came after media reports showed that Hong Kong and U.S.-based activists discovered that their accounts were suspended.

In a blog post on Thursday, Zoom confirmed the reports, acknowledging that China notified them in late May and early June of four public virtual events hosted on the app.

The blog post added that China claimed that the activities were illegal and asked that the events and their hosts’ accounts be shut down. Zoom claimed that it determined that most of the participants in three of the events came from China and terminated their accounts. Then, the host accounts for the events were suspended.

“Zoom does not currently have the ability to remove specific participants from a meeting or block participants from a certain country from joining a meeting,” the company said.

Of the three accounts however, none were based in mainland China.  Two belonged to activists based in America and the third to an activist in Hong Kong. The company did vow to no longer block the accounts of users outside of mainland China, even if Beijing’s asked them to. However the company did not elaborate on how it would deal with these types of requests that affect users inside mainland China. Rather, the company simply said that they would design technology to block users based on their geographic location.

“This will enable us to comply with requests from local authorities when they determine activity on our platform is illegal within their borders; however, we will also be able to protect these conversations for participants outside of those borders where the activity is allowed,” the company said.

Last week’s revelation also drew criticism from U.S. lawmakers as a bipartisan group of senators, including Marco Rubio, R-Fla., and Ed Markey, D-Mass., who penned a letter to the company’s CEO Eric Yuan.

In the letter, the officials demanded to know which Chinese laws mandated that ZOOM suspend the accounts of U.S.-based activists Zhou Fengsuo and Wang Dan. The lawmakers also wanted answers regarding why the company shut down the account of Hong Kong based labor leader Lee Cheuk Yan calling the suspensions deeply concerning.

“Your company has admitted that it did so at the request of the Chinese government to comply with the laws of the People’s Republic of China (PRC), because some of the participants resided inside the PRC. … Zoom’s millions of daily users across the world who support and demand basic freedoms deserve answers,” the senators wrote.