Social media services Facebook, WhatsApp and Instagram are back up and running after an outage that lasted almost six hours, Facebook says.
It blamed an internal technical issue, which not only affected Facebook’s services, but reportedly also employees’ work passes and email.
The services were down from about 16:00 GMT until around 22:00 on Monday.
But the company said there was “no evidence that user data was compromised”.
In a statement, Facebook said that the faulty configuration change affected the company’s internal tools and systems which complicated attempts to resolve the problem.
According to the business website Fortune, it also cost Facebook founder Mark Zuckerberg an estimated $6bn (£4.4bn) at one point as shares plummeted.
Mr Zuckerberg has apologised to those affected by the outage.
