Facebook, Instagram and Messenger have crashed leaving thousands unable to login to the social media apps.
The Facebook-owned apps stopped working this morning at around 9am, according to Down Detector.
While the reason for the issues remains unclear, it appears to be affecting people in the UK and Europe.
Some 80% of those who reported problems have said they weren't receiving messages, while 20% couldn't log in.
London appears to be the worst affected area in the UK.

Frustrated social media users have taken to Twitter to vent about the crash.
One user wrote: "Is Facebook Messenger down? I cannot send and receive messages!"
Another said: "Either Facebook messenger is down on my phone or my wifi is extremely poor this morn. Let me text my friends back!"
A third added: "Yeah so Facebook messenger be down or I’m really trippin."
There has been no official acknowledgement of the blip from Facebook or Instagram.
WhatsApp, which is also run by Facebook, does not appear to be having any issues.
With over 2.7 billion monthly active users as of the second quarter of 2020, Facebook is the biggest social network worldwide.