SAN FRANCISCO — Facebook will remove posts, photos and other content that mislead people about the U.S. census starting next year, aiming to prevent malicious actors from interfering in a critical, once-in-a-decade process that determines political representation, the social media company announced Thursday.

The new policies come as civil rights leaders urge Facebook to act more aggressively against content that targets vulnerable communities, including people of color and immigrants, who may be most influenced by social media misinformation about voting.

Under the new rules, Facebook will ban posts from misrepresenting when and how the census occurs, who can participate and what happens to the personal information people submit to the government, company executives said. The policies also apply to ads, limiting even what politicians can say, despite rules that otherwise allow office seekers to lie in Facebook posts that they pay to promote to the company’s more than 2 billion users.

“As the format of the census evolves, so do the ways that people share information about the census,” wrote Kevin Martin, the vice president of U.S. public policy at Facebook, and Samidh Chakrabarti, the company’s director of product management for civic engagement. “This means we have to be more vigilant about protecting against census interference across posts and ads on Facebook and Instagram and help promote an accurate count of every person in the country.”

Facebook’s announcement comes almost six months after it first said it would clamp down on inaccurate or misleading posts involving the 2020 Census, which will be used to determine how many seats in the House of Representatives are allotted to each state and help set the boundaries for federal congressional districts. The social networking giant faces the prospect that malicious actors in the United States and abroad could try to undermine the process in the same way that Russian malefactors seized on the 2016 presidential election to sow social unrest online.

In response, Facebook and other tech giants, including Google and Twitter, have huddled with government officials in recent months to prevent census disinformation. And other companies have unveiled their own defensive measures: Google in December said it prohibited ads and YouTube videos that aim to misinform about the 2020 count. Twitter’s rules, meanwhile, prohibit “misleading information about how to participate in an election or other civic event.”

But concerns still have lingered, particularly among civil rights advocates such as the Leadership Conference on Civil and Human Rights, Color of Change and the Lawyers’ Committee for Civil Rights Under Law, which met with Facebook chief executive Mark Zuckerberg this fall.

The groups specifically took issue with Facebook’s policy allowing office seekers to lie in ads, months after President Trump’s 2020 campaign paid to promote falsehoods about Democratic rival Joe Biden. In a Nov. 8 letter, they expressed alarm that “foreign or domestic actors” could seize on the widely controversial rules to “harm minority and vulnerable populations that have been consistently targeted throughout our nation’s history.”

On Thursday, at least one of those groups offered early support for Facebook’s plans. “Notably, Facebook will hold all users, including politicians, accountable for adhering to this policy, an important step toward ensuring fair and full participation in the 2020 Census,” said Vanita Gupta, president of the Leadership Conference on Civil and Human Rights.

But, Gupta added, “Any good policy is meaningless without proper enforcement.”

Facebook’s new policies around the census are tougher than its approach toward other content on the site. The rules prohibit people from misrepresenting the effectiveness of the census or claiming there could be “law enforcement consequences” for those who participate, responding to concerns that malicious actors might try to use Facebook to scare immigrants into not sharing their information. Such posts have appeared on social media sites in connection with elections in an attempt to push immigrants in the United States away from voting.

Migrants in the country illegally traditionally have been counted in the census. The Trump administration in July dropped its effort to add a question about citizenship to the census after the Supreme Court ruled its rationale for the question was “contrived.”

“We believe that the partnerships, policies and products we’ve developed this year have put us on strong footing heading into next year’s census,” Facebook executives said.