MOSCOW — Russia, which American intelligence agencies said spread its fair share of misinformation during the 2016 United States election, says it will crack down on “fake news” at home, with a proposed law that critics say could limit freedom of speech on the internet.

The bill, submitted by lawmakers from the governing party, United Russia, proposes holding social networks accountable for “inaccurate” comments users post. Under existing Russian law, social media users can be punished for content deemed to promote homosexuality, to threaten public order or to be “extremist” in nature, with fines as well as prison time.

Under the proposed rule, part of a creeping crackdown on digital rights under President Vladimir V. Putin, websites with more than 100,000 daily visitors and a commenting feature must take down factually inaccurate posts or face a fine of up to 50 million rubles, about $800,000.

The bill gives social media companies 24 hours to delete “inaccurate” information after being notified of its existence, raising concerns that moderators will be left to interpret the term, which is vaguely defined in the measure.