Facebook and Instagram are to ban users from advertising and selling firearms to stop people avoiding background checks.
The crackdown only applies to public posts and won't scan private messages.
The rule aims to stamp out people trading guns to one another on both social networks following concerns that they were being used as a way to get around background checks. Despite the clampdown, licensed businesses will still be able to continue promote guns as they have always been banned from accepting orders and making sales on both networks.
The change bolsters Facebook’s regulated goods policy, first introduced in March 2014 to ban people selling marijuana, pharmaceuticals and illegal drugs as well as block kids from seeing gun ads.
The development comes after a string of shootings in the US roused president Barack Obama to plead with social media networks to clampdown on gun sales.