WASHINGTON (AFP) - YouTube has unveiled a fresh effort to stem the spread of coronavirus misinformation with a "news shelf" on its homepage promoting "authoritative content".

The move is the latest by technology platforms to curb the sharing of rumours and hoaxes about the pandemic, with Facebook having announced a similar action this week.

"We want everyone to have access to authoritative content during this trying time, so we're launching a Covid-19 news shelf on our homepage in 16 countries," the Google-owned video sharing service said in a statement on Twitter late on Thursday (March 19).

"We'll expand to more countries, as well."

YouTube earlier this week joined other large US Internet platforms in a joint effort to root out misinformation about the coronavirus pandemic.

The move comes amid an unprecedented global response to the pandemic as well as increased claims that the virus itself is a hoax.

Facebook on Wednesday said it would make a similar move to place authoritative information at the top of user feeds.

The Facebook information hub was built in collaboration with health organisations and was rolled out in the United States and Europe, with plans to expand it to other locations.

"Our goal is to put authoritative information in front of everyone who uses our services," Facebook chief executive Mark Zuckerberg said.

Twitter this week expanded its safety rules to remove tweets that could put more people at risk.

Twitter's safety team said it would ban "content that increases the chance that someone contracts or transmits the virus", including denial of expert guidance or encouragement of the use of fake or ineffective treatments.