"The decision was made to block access to Facebook" as early as Friday, Roskomnadzor announced on Telegram.
AFP journalists in Russia have seen that the social network no longer works without a VPN.
Roskomnadzor justified his decision by accusing Facebook, owned by the American Meta, of "discrimination" against Russian media such as the Ministry of Defense television Zvezda, the news agency Ria Novosti, the international channel RT or the sites Lenta.ru and Gazeta.ru.
Moscow had already announced a week ago "limiting access" and "slowing down" the operation of Facebook, which had restricted the functionality of Russian media accounts in question.
According to the Russian regulator, these restrictions "violate the key principles of free dissemination of information and unhindered access of Russian users to Russian media on foreign internet platforms".
Since the beginning of Moscow's invasion of Ukraine on February 24, the Russian authorities have stepped up their pressure against the last independent media and on major social networks.
Russian deputies thus introduced a law on Friday punishing heavy penalties for those who disseminate "false information about the army".
Roskomnadzor also restricted access to the BBC, German international radio and television Deutsche Welle (DW), independent Russian site Meduza (based in Riga), Radio Svoboda, Russian branch of RFE/RL, Voice of America and other unnamed news sites.
© 2022 AFP