Facebook logo is seen on an android mobile phone in front of a computer screen.
In a blog post published Monday, the company said it blocked a total of 30 Facebook accounts and 85 Instagram accounts which "may be engaged in coordinated inauthentic behavior". The Instagram accounts were mostly in English, while the Facebook accounts were in French or Russian, the company said.
She said Russian "trolls", or provocateurs, were likely stoking sentiments on both ends of the USA political spectrum "but that the network we now have identified is targeting the far right of American political discourse".
Gleicher said the company typically waits until it is further along in such a probe before publicly acknowledging the steps it takes to remove suspicious accounts, but "given that we are only one day away from important elections in the USA, we wanted to let people know about the action we've taken and the facts as we know them today".
Facebook said it planned to release more information as the investigation continues.
The social network said it needed to do further analysis to decide if the accounts are linked to Russia's Internet Research Agency or another group.
CEO Mark Zuckerberg warned last quarter that the company's sales growth would slow significantly for the remainder 2018 as it ramps up spending on safety and security.
Facebook has since tried to clamp down on nefarious foreign actors.
A spokesperson for Facebook declined to disclose any other details about the extent of the current investigation, including which USA law enforcement agency tipped off Facebook.
Facebook, which has been blamed for doing too little to prevent misinformation efforts by Russian Federation and others in the 2016 USA election, now wants the world to know it is taking aggressive steps with initiatives like the war room.
"Finding and removing abuse is a constant challenge".