Russia is increasing its efforts to manufacture and disseminate phony videos and bogus information to undermine the legitimacy of the US election and exacerbate already deep divisions, US intelligence agencies warned late Monday.

"These efforts risk inciting violence, including against election officials. We anticipate Russian actors will release additional manufactured content with these themes through Election Day and in the days and weeks after polls close" according to a joint statement from the Office of the Director of National Intelligence, the FBI and the Department of Homeland Security.