Facebook, Twitter, and Alphabet have collectively removed hundreds of accounts tied to an alleged Iranian propaganda operation on Tuesday.
Facebook also took down a second campaign it said was linked to Russia.
More than 650 Facebook pages and groups were said to have been identified as “misleading”, according to founder and chief executive Mark Zuckerberg.
Meanwhile Twitter said it suspended 284 accounts with apparent links to Iran.
It comes a day after Microsoft said it had thwarted Russian cyber-attacks against US conservative groups.
On Tuesday, Facebook said it had discovered multiple accounts that displayed “inauthentic behaviour” linked to campaigns that originated in Iran and Russia following investigations that spanned “many months”.
“We ban this kind of behaviour because we want people to be able to trust the connections they make,” the company said in a statement.
Although the investigation was still in progress, the social media network added, the campaign appeared to be targeting people across multiple internet services in the Middle East, Latin America, the UK and the US.
On Monday, Microsoft said Russian hackers had tried to steal data from political organisations, including the International Republican Institute and the Hudson Institute think tanks.
However the software company said these attempts had been thwarted after its security staff won control of six net domains mimicking their websites.
Microsoft said the Fancy Bear hacking group had been behind the attacks.
Microsoft’s action comes a month after the US charged 12 Russian intelligence officers with hacking computer networks used by Hillary Clinton and the Democratic Party.
