Facebook has removed its self-hosted, fast-loading article format Instant Articles meant for mobile from the Messenger app. The feature was originally designed to run in the News Feed in the Facebook core app and will continue to do so, Tech Crunch reported late Tuesday. "As we continue to refine and improve Instant Articles and in order to have the greatest impact on people and publishers, we are focusing our investment in Instant Articles in the Facebook core app and are no longer offering Instant Articles in Messenger," a Facebook spokesperson was quoted as saying. Instant Articles was an article format launched in 2015 to speed up page load time in the Facebook core app by ten times compared to the mobile web and was later expanded to Messenger. Several high profile publications and publishers either pulled, scaled back or never participated in Instant Articles in the first place because of the lack of monetization on the platform. There have also been issues with traffic reporting with the format. Facebook has confirmed that it is collaborating with publishers on a paid-content model that it will start testing later this year, the report added. The new model will allow readers to subscribe and pay for publications directly from Facebook's mobile app.