Facebook is testing a new "context" button that would allow users to get more information about who is supplying a news story. In the latest move by the US social media company to curb so-called fake news, the new feature will provide instant information about the source of a news article. 

A Facebook blog post signed by product managers Andrew Anker, Sara Su and Jeff Smith said: "We are testing a button that people can tap to easily access additional information without needing to go elsewhere. "The additional contextual information is pulled from across Facebook and other sources, such as information from the publisher's Wikipedia entry." 

In some cases if the information is not available, "Facebook will let users know, which can also be helpful context", the blog said. "Helping people access this important contextual information can help them evaluate if articles are from a publisher they trust, and if the story itself is credible." Facebook has been battling to stem the flood of fake news, hoaxes and disinformation which dogged the 2016 US presidential election. 

Some of the fake news is believed to have come from Russian sources. The announcement of the "context" button comes after US senators said they would ask executives from Facebook, Google and Twitter to testify at a hearing in November on alleged Russian efforts to manipulate internet platforms during the election campaign. 

A Facebook source said a representative of the social network would attend the hearing but refused to say who. Senator Mark Warner, a member of the intelligence committee, said "it's important that the three companies that we've invited - Google, Twitter, and Facebook - will appear in a public hearing" to testify on how they will curb misinformation and manipulation. 

Facebook earlier announced it plans to recruit more than 1,000 people to thwart deceptive ads designed to interfere in and influence. It also turned over to Congress 3,000 Russia-linked ads that were posted ahead of the US election.