The Belarusian security service KGB has deployed fake social media accounts during the migrant crisis.
Employees posed as activists and journalists to stir up unrest.
Meta has since removed the profiles, reports it in a blog.
Meta, the new name of parent company Facebook, has deleted 41 accounts and five groups on Facebook.
Four profiles have been blocked on Instagram.
Belarus is at loggerheads with the European Union and has sent large numbers of migrants to the border with Poland in recent months.
According to Meta, the Polish authorities were criticized in various languages through the fake profiles.
These included reports that migrants have been mistreated and intimidated by Polish border guards.
Those behind the operation tried to keep their identities a secret, according to Meta.
"But our investigation revealed a link to the KGB in Belarus."
The tech giant does not explain what data that would show.
The KGB has kept the name of the infamous security service from the Soviet Union and is the mainstay of President Alexander Lukashenko, who has been in power in the Eastern European country since 1994.
The security service has not yet responded to Meta's accusations.Keywords: