Facebook has removed hundreds of social media accounts and banned an Israeli firm due to “coordinated inauthentic behaviour” mainly targeting Africa.
The fake accounts often posted on political news, including on elections in various countries, the firm said.
Facebook has faced rising criticism for failing to stamp out misinformation on its platform.
It launched a fact-checking programme in 2016 shortly after Donald Trump became US president.
In a blog post, Facebook said it had removed 265 social media accounts that originated in Israel and focused on Nigeria, Senegal, Togo, Angola, Niger and Tunisia, along with “some activity” in Latin America and South East Asia.
An investigation found that some of the activity was linked to Israeli company Archimedes Group, Mr Gleicher said.