LONDON — Facebook identified two disinformation campaigns originating from Russia — including one tied to an agency controlled by the Kremlin — that were targeted at users in Europe and Central Asia. The company said on Thursday it had deleted nearly 500 pages and accounts that had posted the misleading messages.

Many of the pages were discovered to be linked to employees of Sputnik, an agency controlled by the Russian government that was established to spread reports and information sympathetic to Russia. It used independent news pages on topics like weather, travel and sports to mask its efforts, Facebook said.

The company has been under pressure to more aggressively address the spread of misinformation, and to counter manipulation on its social network that is aimed at stirring division and discord, ever since it became evident that Russia used it to target groups of voters, sow division and spread false information in order to sway the 2016 presidential election. Mark Zuckerberg, Facebook’s chief executive, has said the detection of suspicious activity is a top priority.

But on a platform of two billion users, disinformation campaigns are hard to detect, and Facebook remains a gathering ground for groups eager to spread disinformation to the widest audience possible.