Facebook has revealed that around 10 million people viewed the political ads taken out by a Russian entity on its platform. In a new blog post, the social network announced that the majority of the advertisements "focus on divisive social and political messages across the ideological spectrum."

In a statement to congressional investigators last month, Facebook said pro-Kremlin "troll farm" The Internet Research Agency paid $100,000 to place more than 3000 ads on its service. The company had released details of the ads only to special counsel Robert Mueller, who is leading the investigation into Russia's election meddling, but later shared the information "more broadly" with congress.

Elliot Schrage, Facebook's vice-president of policy and communications, writes that the ads touch on topics "from LGBT matters to race issues to immigration to gun rights." 44 percent of them were displayed before the US election, with the remaining 56 percent arriving after November 8, 2016.

Around 25 percent of the ads weren't seen by anyone as they didn't target users' interests. Additionally, it turns out that 50 percent of the ads cost under $3, while 99 percent of all the ads cost $1000 or less.

The Washington Post reports that one of the advertisements featured a black woman pulling the trigger of an empty rifle. Another showed Hillary Clinton behind bars. A number of the ads encouraged people to follow Pages on these issues.

Facebook says that it reviews millions of ads each week, and about 8 million people report them each day, meaning it can't catch every one that breaks the rules. It has promised, however, to start requiring that advertisers "confirm the business or organization they represent," which should help identify fakes.

Facebook also said it would make advertising more transparent, tighten restrictions on content, and strengthen enforcement against improper ads. It intends to hire 1000 more people to review its ads globally.