A coalition of civil rights groups called upon Facebook this week to conduct an independent review of how its policies may have allowed hate groups and political entities to stoke racial and religious resentment or violence.

Muslim Advocates, along with more than a dozen groups including the Southern Poverty Law Center and the NAACP, sent a four-page letter to Facebook outlining reported instances of posts, pages and ads used to promote hate against Muslims, African Americans, immigrants and sexual minorities.

The groups have long complained to Facebook about the bigotry and racism promoted on its platform, meeting with its chief operating officer, Sheryl Sandberg, earlier in October about their concerns.

[A white man called her kids the n-word. Facebook stopped her from sharing it.]

“Even though Facebook has listened to our concerns, they haven’t made meaningful changes to the way the platform is being used,” said Madihha Ahussain, special counsel for anti-Muslim bigotry at Muslim Advocates, in an interview with The Washington Post on Monday.

Lawyers for Facebook, Google and Twitter were scheduled to testify at congressional hearings that began Tuesday on Russian meddling in the 2016 presidential election.

The coalition pointed to numerous media reports of Facebook being used to sow divisions among Americans. Russian operatives set up fake Facebook accounts posing as U.S. citizens concerned about an influx of refugees and promoting anti-immigrant rhetoric. The operatives even managed to orchestrate an anti-refugee rally in Idaho last year.

Russian operatives also bought Facebook ads alternately impersonating Black Lives Matter and describing it as a threat. The ads targeted residents of Baltimore and Ferguson, Mo. — communities on edge over police killings of black men — in an apparent attempt to further inflame political discord.

[Russian content on Facebook, Google and Twitter reached far more users than companies first disclosed, congressional testimony says]

“We were alarmed to see your platform being abused to promote bigotry, and especially disappointed that it has taken media exposure and congressional oversight to give a degree of transparency into your practices,” the letter said. “It is important to keep in mind that pervasive bigotry has long existed on your platform, and the Russian operatives simply exploited the hateful content and activity already present.”

The groups said they were concerned about Facebook’s apparent unwillingness to institute safeguards against such manipulation. The groups want the company to publicly disclose all the ads, pages, accounts, events and posts that have been traced back to Russian operatives.

Facebook said in a statement to The Post that it was “grateful for the feedback” in the letter.

“There is no place for hate on Facebook,” said Erin Egan, vice president of U.S. public policy for Facebook. “This is an ongoing process and we are committed to listening and learning from communities that face attacks based on factors such as race, religion, ethnicity, gender, and sexual orientation. We are taking action in the form of investments in security and making improvements to our policies and tools.”

Chief executive Mark Zuckerberg had initially dismissed Facebook’s role in the spread of fake news, but the company subsequently said that it was fully cooperating with the investigations into Russian interference in the U.S. election. Facebook said last week in response to congressional pressure that it would be more transparent about who is paying for political ads.

Ahussain said civil rights groups have also repeatedly asked Facebook to address white supremacists’ open attacks on African Americans and Muslims even as the company disproportionately censored black and Muslim voices. The company has previously acknowledged the problem, telling The Post in July that it was working to change its policies as well as its tools to police content.

The groups want Facebook to develop clear procedures for reviewing content flagged as hate speech and to produce an annual report on the company's effectiveness in tracking and stopping hate speech.

“This is not just about what we are dealing with right now with these Russian ads. These are about long-term concerns these communities have raised over time,” Ahussain said. “Facebook has the opportunity to set the tone and transform the way people have taken advantage of the weaknesses within the platform.”