Facebook along with its Instagram and WhatsApp services began returning online late yesterday evening after a massive and lengthy outage that began this afternoon.
While access to Facebook and Instagram appeared to have been largely restored just before midnight, users were still reporting issues with WhatsApp.
Facebook's family of apps essentially "disappeared" from the internet for several hours after a traffic routing problem that made the sites unreachable by users, according to Cloudflare, a website security company.
In a statement this evening, the social media giant apologised for the outage and said services were beginning to come back online.
It said: "To the huge community of people and businesses around the world who depend on us: we're sorry. We've been working hard to restore access to our apps and services and are happy to report they are coming back online now. Thank you for bearing with us."
The platforms had earlier confirmed on Twitter they were aware of issues and were working to resolve them.
Facebook's chief technology officer Mike Schroepfer expressed "sincere apologies" to users via Twitter.
He said: "We are experiencing networking issues and teams are working as fast as possible to debug and restore as fast as possible."
According to web service monitoring platform DownDetector, thousands of people reported outages before 5pm today.
Data on its website showed that almost 50,000 people had reported the outages on Facebook.
Most complaints cited issues with the website (72%), while others were linked to issues with the server connection and the app.
Moe than 60,000 had complained about WhatsApp, with 43% reporting issues with the app itself, while 28% cited the server connection and 28% relating to sending messages.
More than 30,000 Instagram users also had similar complaints, with 51% relating to the app, 26% over the server connection and 23% citing the website.
A graph on the DownDetector website showed a clear spike from after 4pm.
Whatsapp had said on Twitter: "We're aware that some people are experiencing issues with WhatsApp at the moment.
"We're working to get things back to normal and will send an update here as soon as possible. Thanks for your patience."
Facebook account tweeted: "We're aware that some people are having trouble accessing our apps and products.
"We're working to get things back to normal as quickly as possible, and we apologise for any inconvenience."
Instagram said: "Instagram and friends are having a little bit of a hard time right now, and you may be having issues using them. Bear with us, we're on it."
Vodafone Ireland had also tweeted that it was experiencing technical issues.
There is currently a global outage across several social media platforms. This is impacting our data network performance. We will continue to post updates as they become available.— Vodafone Ireland (@VodafoneIreland) October 4, 2021