New York (CNN Business) Twitter has apologized for suspending accounts that were critical of the Chinese government's response to the Tiananmen Square protests of June 4, 1989.

wrote on its public policy feed Saturday that the suspended accounts were swept up in a weekly effort to crack down on "spam and other inauthentic behaviors."

"Sometimes our routine actions catch false positives or we make errors. We apologize," Twitter said. It added that the suspended accounts had not been reported by the Chinese government.

The suspension of the accounts, both inside and outside China, elicited criticism from US Senator Marco Rubio, who tweeted the company was silencing voices on behalf of the Chinese government.

"Twitter has apparently suspended a large number accounts that are critical of #China including accounts of people outside of China. Twitter has become a Chinese govt censor," he said.

Activists critical of the Chinese government had been speaking out on the platform in the days leading up to June 4, which will mark the 30th anniversary of the massacre of unarmed citizens by soldiers in Beijing's Tiananmen Square. Chinese troops ended several weeks of protests by firing at civilians, killing hundreds, if not thousands, of people.

The Twitter accounts had taken aim at the policies of China's Communist government and its handling of the crackdown in Tiananmen Square.

The Chinese government rarely mentions the incident and has worked for years to censor all mention of it within the country.

On the anniversary, there no public memorials or protests around the issue are expected in mainland China, because of tight government suppression.