PragerU's Facebook Page

Facebook is again being accused of blocking conservative voices.

The social network apologized Friday to conservative group PragerU, saying it "mistakenly" removed several videos from the nonprofit's Facebook page.

In a tweet, Facebook said: "We mistakenly removed these videos and have restored them because they don't break our standards. This will reverse any reduction in content distribution you've experienced. We're very sorry and are continuing to look into what happened with you Page."

We mistakenly removed these videos and have restored them because they don't break our standards. This will reverse any reduction in content distribution you’ve experienced. We’re very sorry and are continuing to look into what happened with your Page. — Facebook (@facebook) August 18, 2018

PragerU on Friday said Facebook blocked nine of its videos and deleted at least two for "hate speech," including one video called Make Men Masculine Again.

"This is very troubling behavior from the world's largest social network," Craig Strazzeri, chief marketing officer at PragerU, said in a statement. "Not only are they obviously ratcheting up their algorithms to target mainstream, conservative content and labeling it as hate speech, but they're now completely blocking our posts from public view."

The tech giant has been under scrutiny over controversial content on its platform. From Russians using Facebook to spread misinformation to the Cambridge Analytica data scandal to removing conspiracy theorist Alex Jones from its platform, the company is trying to figure out how to police content on its site. In April, Facebook faced a backlash after it mistakenly removed videos of two sisters known as Diamond and Silk who are avid supporters of President Trump.

PragerU is a nonprofit group co-founded by conservative radio show host Dennis Prager that covers political and economic topics in short videos. Its Facebook page has more than 3 million followers.

Facebook and PragerU didn't immediately respond to requests for comment.