UPDATE 1-Facebook uncovers more disinformation activity tied to Iran -source

Facebook Inc has uncovered Iranian disinformation activity on its platform and taken steps to mitigate its impact, a person familiar with the situation said on Friday, marking the latest effort by a social media company to protect users from such campaigns

The person, who was not authorized to discuss the activity ahead of an announcement by Facebook, said that the company planned to unveil details later on Friday.

Facebook, along with Twitter Inc and Alphabet Inc, in August removed hundreds of accounts tied to an Iranian propaganda effort. Facebook also disclosed it had taken down a second campaign linked to Russia.

Social media companies have increasingly targeted foreign interference on their platforms following criticism that they did not do enough to detect, halt and disclose Russian efforts to use their platforms to influence the outcome of the 2016 U.S. presidential race.

Iran and Russia have denied allegations that they have used social media platforms to launch disinformation campaigns.