Facebook says it found Iran-based propaganda effort

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SAN FRANCISCO — Facebook said on Tuesday it had removed hundreds of Iran-based pages, groups and accounts, alleging that the network was linked to Iranian state media and tried to covertly spread political content to people on four continents including in the U.S.

Facebook said in a blog post that the 652 pages, groups and accounts were in violation of its terms of service because they were engaged in “coordinated inauthentic behavior.”

The announcement adds to a steady drumbeat of efforts by U.S. tech companies to detect and stop hacking attempts by suspected foreign agents who might want to meddle in the Nov. 6 midterm elections.

Earlier on Tuesday, Microsoft said it had shut down six websites created by a group tied to Russian intelligence that sought to spoof conservative U.S. institutions including the U.S. Senate. Russian authorities denied the allegations.

Facebook said last month that it had removed 32 pages and accounts from its platform and from Instagram that the company said were trying to covertly spread divisive political messages.

Facebook said its investigation into the Iran-based pages was ongoing and that the company had shared its findings with U.S. and British authorities.

The investigation may have implications for how the social media company complies with U.S. sanctions on Iran.

Facebook said that because of the sanctions it takes steps to prevent people in Iran from using its advertising tools, but that the accounts in question had purchased more than $12,000 in ads on Facebook and Instagram.

“We’ll make changes to better detect people who try to evade our sanctions compliance tools and prevent them from advertising,” Nathaniel Gleicher, Facebook’s head of cybersecurity policy, said in the blog post.