Hillary Clinton has spoken out against the "epidemic" of fake news in one of her first public addresses since losing the US Presidential election.

The former Democratic presidential nominee said the rise of fake news is a "danger that must be addressed and addressed quickly".

Speaking on Capitol Hill at the unveiling of a portrait in honour of retiring Senate Minority Leader Harry Reid, she called on officials in the public and private sectors to combat the spread of "malicious false propaganda".

Mrs Clinton said: "The epidemic of malicious fake news and false propaganda that flooded social media over the past year, it's now clear that so-called fake news can have real world consequences.

"This isn't about politics or partisanship. Lives are at risk, lives of ordinary people just trying to go about their days.

"It's a danger that must be addressed and addressed quickly."

It comes after a man was arrested on Sunday after firing an assault rifle at a pizza parlour in Washington DC after claiming he had come to investigate false online stories about a child sex trafficking ring run by prominent Democrats at the restaurant.

Edgar Maddison Welch, 28, has been jailed after he brought an AR-15 rifle to the Comet Ping Pong restaurant and opened fire.

He has refused to dismiss the online claims.