The announcement came shortly after US law enforcement and intelligence agencies said that Americans should be wary of Russian attempts to spread fake news . The election is Tuesday.
A study published last week found that misinformation on social media was spreading at a greater rate than during the run- up to the 2016 presidential vote, which Russia is accused of manipulating through a vast propaganda campaign in favour of Donald Trump, the eventual winner .
" On Sunday evening , US law enforcement contacted us about online activity that they recently discovered and which they believe may be linked to foreign entities, " Facebook head of cybersecurity policy Nathaniel Gleicher said in a blog post.
" We immediately blocked these accounts and are now investigating them in more detail. "
The investigation so far identified around 30 Facebook accounts and 85 Instagram accounts that appeared to be engaged in " coordinated inauthentic behaviour , " Gleicher said .
He added that all the Facebook pages associated with the accounts appeared to be in French or Russian .
The Instagram accounts were mostly in English, with some " focused on celebrities, others political debate . "
" Typically, we would be further along with our analysis before announcing anything publicly , " Gleicher said .
" But given that we are only one day away from important elections in the US, we wanted to let people know about the action we ' ve taken and the facts as we know them today. "
( AFP)