SAN FRANCISCO, Sept 4 (Reuters) - Facebook Inc on Friday removed the pages of U.S. right-wing group Patriot Prayer and its founder Joey Gibson, a company spokesman told Reuters.

Patriot Prayer has hosted dozens of pro-gun, pro-Trump rallies. Attendees have repeatedly clashed with left-wing groups around Portland, Oregon, where one group supporter was killed this week.

The victim, 39-year-old Aaron Danielson, was walking home on Saturday night after a pro-Trump demonstration in the city when he was shot.

Facebook took down the pages as part of efforts to remove "violent social militias" from its social networks, spokesman Andy Stone said.

The company updated its policies last month to ban groups that demonstrate significant risks to public safety.

Its dangerous organizations policy now includes groups that celebrate violent acts or suggest they will use weapons, even if they are not directly organizing violence.

In a statement posted on Patriot Prayer's website, Gibson accused Facebook of a double standard.

"Antifa groups murdered my friend while he was walking home, and instead of the multibillion dollar company banning Portland Antifa pages they ban Patriot Prayer, Joey Gibson and several other grandmas that are admins," he wrote.

Antifa is a largely unstructured, far-left movement whose followers broadly aim to confront those they view as authoritarian or racist.

Gibson espouses non-violence but is accused by anti-fascist groups of provoking confrontations.

After the shooting of Danielson he cautioned supporters not to seek revenge, but rather "push back politically, spiritually."

As of earlier this week, the Patriot Prayer page had nearly 45,000 followers on Facebook. It was created in 2017.

Facebook last week removed content associated with the Kenosha Guard, a group which had posted a "call to arms" in Kenosha, Wisconsin.

The company acted the day after two people were shot and killed at protests in the city, which broke out in response to the police shooting of a Black man earlier that week.

Users had flagged the material to Facebook 455 times but were told initially it did not violate the company's policies, BuzzFeed reported https://www.buzzfeednews.com/article/ryanmac/facebook-failed-kenosha. (Reporting by Katie Paul and Andrew Hay; Editing by Sandra Maler and Rosalba O'Brien)