Google has also been working with the cybersecurity group FireEye, which has been providing Google with information on an Iran-based misinformation operation. FireEye identified three email accounts, three YouTube channels and three Google+ accounts linked to that operation, which Google subsequently took down.

FireEye also tipped off Facebook to the Iranian operation, and Facebook detailed its response to that information and findings from its own investigations earlier this week. You can check out the full FireEye report here. Twitter also announced this week that it suspended 284 accounts believed to have originated from Iran for "engaging in coordinated manipulation."

In conjunction to the intelligence provided by FireEye, Google also investigated other suspicious groups linked to Iran. The company identified and removed 39 YouTube channels, six Blogger blogs and 13 Google+ accounts it believed to be connected to the Islamic Republic of Iran Broadcasting. Relevant videos on the now-terminated YouTube channels had garnered 13,466 views in the US.

Additionally, Google says it's still monitoring its platforms for actors associated with the Russia-based Internet Research Agency -- which was involved in spreading political discord in the US ahead of the 2016 presidential election -- and has removed one Blogger account and 42 YouTube channels that published 58 English-language political videos that appear to be linked to the group.

"Our investigations on these topics are ongoing and we will continue to share our findings with law enforcement and other relevant government entities in the US and elsewhere, as well as with others in the industry," Google said.