Facebook, Instagram and WhatsApp went down today with social media users throughout Ireland and worldwide left frustrated.
All three of the social networks - which belong to Facebook - started having issues at 11am.
Monitoring website downdetector.ie received hundreds of complaints regarding the problems.
Hundreds of people also took to Twitter to report the issues.
Those hoping to log on were being presented with an error message saying the site "can't be reached".
As a result, people were unable to also access Facebook Messenger on PCs or laptops.
One user said: "Instagram, Facebook and WhatsApp are down. Thank you Zuckerburg, great service."
A second chipped in: "Facebook, we have a problem.
Jamie Strachan tweeted: "Here we go again. Facebook and Instagram are down and now everyone will rush to Twitter to complain about it."
It is not clear at this stage what the problem was, however normal service did resume for a time on Facebook just after 12pm noon before issues persisted. Facebook then came back fully just after 2pm.
The issue also appears to have hit other countries - with users in Morocco, Ukraine, the Philippines, Nepal and Greece also complaining.
Facebook has yet to comment on the outage.
Many people seem baffled as to why the sites were experiencing issues yet again as this is far from the first time the sites have gone dark.
They have been plagued with technical difficulties, with outages lasting hours sometimes.
Last month users were unable to post updates after Facebook went down for 14 hours.
Facebook and Instagram both started experiencing difficulty at around 4pm GMT on March 13.
Error messages on both sites stated: "Oops... Something went wrong. We're working on getting it fixed as soon as we can."
The hashtags #FacebookDown and #InstagramDown were used more than 150,000 times as the outage went on.
It was described as the "most severe" outage in Facebook's history.
The last time Facebook had a disruption of that magnitude was in 2008, when the site had 150 million users - compared with around 2.3 billion monthly users today.
Facebook confirmed at the time that the issue was triggered by a 'server configuration change'.
