Facebook says access to its network of social media services has largely been restored after a global outage lasting more than six hours. US media say it could be the longest problem of its kind to hit the tech giant in more than a decade.
The problem also affected WhatsApp and Instagram, which are owned by Facebook. The company apologized via rival service Twitter, saying, "To the huge community of people and businesses around the world who depend on us: we're sorry."
Facebook is yet to reveal the details of what caused the outage, and which parts of the world were affected.