US Special Counsel Robert Mueller on Friday indicted 13 Russian nationals and three companies accused of running a secret campaign to tilt the 2016 presidential election. The unsealed indictment details a stunning operation that began in 2014 and aimed to sow social division inside the United States, influence US politics "including the presidential election of 2016."

Mueller alleges the campaign - under the direction of Yevgeny Prigozhin, a close ally of Vladimir Putin - by mid-2016 became focused on boosting Donald Trump and demeaning his rivals. It allegedly involved "hundreds" of people working in shifts and with a budget of millions of dollars.

According to the indictment, the group posed as US citizens on Facebook, Twitter, YouTube and Instagram and posted content that reached "significant numbers" of Americans. The group was allegedly in contact with "unwitting" members of the Trump campaign, but had a broader "strategic goal to sow discord in the US political system."

Copyright Agence France-Presse, 2018