The social networks are currently not working on desktop but it isn’t clear what the problem is.
Those hoping to log on are being presented with an error message saying the site “can’t be reached”.
As a result, people are unable to also access Facebook Messenger on PCs or laptops.
Downdetector.co.uk has received more than 6,000 complaints since 11am today – with millions across the world affected.
There are also reports WhatsApp, which is owned by Facebook, is not currently working.
‘THANK YOU ZUCKERBERG’
Some users across the globe have claimed their messages are not being sent or received.
The issue also appears to have hit other countries – with users in Morocco, Ukraine, the Philippines and Greece among those complaining.
Frustrated users have now taken to Twitter to slam Facebook for the outage.
One wrote: “Instagram, Facebook and WhatsApp are down. Thank you Zuckerburg, great service.”
Another fumed: “Facebook, we have a problem.”
It comes just one month after Facebook experienced its worse ever outage – with both social networks and WhatsApp having issues for 24 hours.
Facebook later apologised and blamed a “server configuration change”.
They have not yet commented on the latest issue.
More to follow…