Hillary Clinton has urged action on "malicious fake news", calling it a dangerous "epidemic" that must be addressed.

The former presidential candidate, who faced a flood of such stories during her election campaign, said there was an "epidemic of malicious fake news and false propaganda that flooded social media over the past year".

Speaking a month after she lost the presidential election, Ms Clinton said: "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, to do their jobs, contribute to their communities."

Ms Clinton made her remarks as she paid tribute to retiring Senate Democratic leader Harry Reid.

Clinton herself has been a target of fake news, with internet postings claiming that a pizza restaurant in Washington was fronting a child sex ring run by Clinton.

On Sunday, a North Carolina man wielding an assault rifle fired a gun inside the restaurant, according to police, who said the suspect told them he had come to "investigate" a fake news report.

Clinton, who served with Reid in her days as a senator, made a wry reference to the relatively low profile she has kept since Donald Trump won the November 8 election, referring to "a few weeks of taking selfies in the woods".