Facebook, Instagram and WhatsApp all experienced significant outages, with users worldwide reporting issues for at least about two hours.
Thousands of people logged complaints on the website downdetector.com, with those using the main Facebook website and app having trouble loading their newsfeed and even logging in.
Facebook Messenger and WhatsApp both failed to send and receive messages, and experienced other connection issues. The Instagram newsfeed also struggled to load and update for some users.
A spokesperson for the company told Sky News: Earlier today, some people may have experienced trouble connecting to the family of apps. The issue has since been resolved; we’re sorry for any inconvenience.
All of the apps and services are owned and run by the social media giant, which almost a month ago to the day experienced one of its longest ever outages.
Facebook announced plans to integrate the three services back in January, prompting calls for an urgent briefing by the Irish data protection commissioner.
It is not clear if technical work connected to this integration is connected to the outage.
Explaining the March incident, Facebook said: Yesterday, we made a server configuration change that triggered a cascading series of issues.
In Saturday’s outage, users across the world including the US, Japan, New Zealand and parts of Europe complained about issues with the services.
Some reported they have been unable to access any of Facebook, Instagram and WhatsApp for almost 24 hours.
As was the case on the previous occasion, many have turned to Twitter to voice their frustration, where global trending topics currently include #FacebookDown, #instagramdown and #whatsappdown.
Alp Toker, the executive director of internet observatory Net Blocks, told Sky News his organisation believed potentially 80% of users worldwide were unable to reach the services.
He said Net Blocks had compiled the figure from on 30,000 network measurements from 2,500 global vantage points which allow the organisation to observe network performance using probes.
At each point in time and at each location, the round-trip time or latency, and any network failure information is relayed and aggregated to get a picture of internet access around the world in real-time.
In this incident, the data lets us rule out a global routing issue as the underlying cause, and we also don’t see the kind of spike in latency prior to the outage usually associated with a DDoS attack.
This points to a different kind of attack or technical issue within Facebook’s data centres, Mr Toker added.
A DDoS attack is a form of internet attack which overwhelms a computer server with requests for information – effectively taking them offline in the way that a bartender could be left unable to serve anyone drinks because they were too busy receiving orders.
After the statement from Facebook that the issue was resolved, Mr Toker confirmed that Net Blocks’ monitoring showed the services had returned to 100% availability.
(c) Sky News 2019: Facebook, Instagram and WhatsApp outages resolved