Facebook suffered a widespread outage lasting roughly 40 minutes on Tuesday affecting users in the United States, Asia, the United Kingdom and Australia.
The social media giant's Instagram service was also briefly inaccessible.
Instagram said on its Twitter account that it was aware of an outage and was working on a fix. There was no immediate statement from Facebook.
Facebook has about 1.25 billion users and Instagram has about 300 million.
News of the Facebook outage set rival social network Twitter alight.
Check back for more on this breaking news story.