Google and Facebook have announced plans to fight the spread of fake news by placing tighter restrictions on how such sites make money from advertising.
Google has revealed it is working on a policy change to its AdSense online advertising network that will prevent websites with misleading content from using it to earn money, while Facebook has said it is updating its advertising policy to restrict adverts appearing alongside "misleading or deceptive" content.
The announcement comes following criticism of social media over the role it played in the US presidential election, and the alleged spread of false information that may have influenced some voters.
Google was also criticised on Monday after the tech giant's search engine promoted an article that contained misleading results of the popular vote in the US election when, in fact, votes were still being counted.
Google apologised for the incident and a spokesman for the company said: "The goal of Search is to provide the most relevant and useful results for our users. In this case we clearly didn't get it right but we are continually working to improve our algorithms."
The technology company said in a statement that it would restrict serving adverts, via AdSense, to websites and pages that "misrepresent, misstate, or conceal information about the publisher, the publisher's content, or the primary purpose of the web property".
Facebook founder Mark Zuckerberg has also denied claims that the social network played any role in influencing the election result, claiming that "99%" of the content on Facebook was authentic.
In a further statement to Reuters on its advertising policy, the social network said: "We do not integrate or display ads in apps or sites containing content that is illegal, misleading or deceptive, which includes fake news."
Facebook added that it would continue to scrutinise publishers on the site to ensure standards were met.
However, the change in policy will not target fake news that is shared by users on their news feeds.