LONDON, Jan. 17 -- Facebook said Thursday it removed hundreds of Russia-linked pages, groups and accounts that it says were part of two big disinformation operations, in its latest effort to fight fake news.

The social media company said it took action after finding two networks "that engaged in coordinated inauthentic behavior" on its Facebook and Instagram platforms.

Facebook's head of cybersecurity policy, Nathaniel Gleicher, said in a blog post that one network operated in countries in Central and Eastern Europe, the Baltics, Central Asia and the Caucasus. The other focused on Ukraine.

The people running the accounts represented themselves as independent news sources and posted on topics like anti-NATO sentiment and protest movemen...