Facebook will stop showing children adverts for gun accessories as part of a policy update, reportedly to try to reduce gun violence in the US following a number of school shootings.
Currently, any user on Facebook can see adverts for a full range of gun attachments, including scopes, holsters and gun-mounted lights.
But from June 21 the social media giant will block underage users from seeing the posts.
According to tech news website the Verge, the decision was linked to a renewed focus on gun violence in America after a number of school shootings.
Last month, ten people were shot dead and 10 others injured after gunman Dimitrios Pagourtzis opened fire inside a high school near Houston, Texas.
The 17-year-old shooter had previously posted pictures of guns to Instagram, a picture sharing site that is owned by Facebook.
The incident had the highest number of fatalities at a school shooting since the massacre in February at Marjorie Stoneman Douglas High School in Parkland, Florida, when 17 people were killed.
A Facebook spokesmen said the decision followed a "regular review" of its policies, which will change to require sellers to “restrict their audiences to at least 18 years of age or over”.
The company, headed up by Mark Zuckerberg, said that sales of weapons, ammunitions, explosives and magazines were already restricted on its network, as were those that helped people modify guns.
It already prohibits the advertising of guns and gun modifications, like silencers and magazines.
Facebook has also recently announced plans to improve the way people were told about how they were being targeted for adverts in the wake of the Cambridge Analytica scandal.