WASHINGTON (Reuters) - Facebook Inc Chief Executive Mark Zuckerberg on Thursday attacked the rapidly growing Chinese short-video app, saying it censored political protest, including in the United States.

Facebook Chairman and CEO Mark Zuckerberg addresses the audience on "the challenges of protecting free speech while combating hate speech online, fighting misinformation, and political data privacy and security," at a forum hosted by Georgetown University's Institute of Politics and Public Service (GU Politics) and the McCourt School of Public Policy in Washington, U.S., October 17, 2019. REUTERS/Carlos Jasso

While delivering an address on free speech at Georgetown University in Washington, Zuckerberg said Facebook social media platforms like WhatsApp were used by protesters and activists everywhere because of its encryption and privacy protection.

But “on TikTok, the Chinese app growing quickly around the world, mentions of these same protests are censored, even here in the U.S.,” he said.

TikTok denied China censors its content, saying it is “not influenced by any foreign government.”

Facebook competes directly with TikTok, especially among younger audiences. The app enable users to create and share short singing and dancing videos that are set to well-known songs, with numerous special effect filters.

Zuckerberg, in a recently leaked recording of him speaking with company employees, noted that TikTok was the first successful Chinese internet product worldwide. “It’s starting to do well in the U.S., especially with young folks.”

Zuckerberg’s Thursday comments came just two weeks after Senator Marco Rubio asked a U.S. national security panel to review TikTok owner Beijing ByteDance Technology Co Ltd’s acquisition of Musical.ly Inc, arguing TikTok is used by the Chinese government to censor politically sensitive content.

In a letter requesting the review, Rubio noted that despite Hong Kong protests dominating international headlines for months, “the app only had a few videos” of the protests.

Rubio said Chinese-owned apps “are increasingly being used to censor content and silence open discussion on topics deemed sensitive by the Chinese Government and Communist Party.”

ByteDance is one of China’s fastest growing startups. It owns the country’s leading news aggregator, Jinri Toutiao, as well as TikTok, which has attracted celebrities like Ariana Grande and Katy Perry along with legions of U.S. teenagers.