Facebook is reportedly running again for some users after prolonged issues for much of the morning.
The issues affected people accessing both Facebook and Facebook-owned Instagram from around 6am this morning.
Others had been able to get into Facebook but were not able to post or reply to anybody.
Facebook responded to concerns this morning, saying that some users may encounter challenges accessing the site as it was down for "maintenance".
A link on the social media site explains that the problems will only be encountered by some users because Facebook doesn't do maintenance on the whole site at the same time.
These issues came off the back of users encountering a number of problems yesterday in accessing Google's YouTube, Gmail and Google Drive services.
The outages have affected people in the US, Central and South America and Europe, according to tweets and the outage-tracking site DownDetector.com.
Facebook quashed some early online rumours that the outages were the result of a distributed denial-of-service (DDos) attack — a type of hack in which attackers flood a company's network.
"The issue is not related to a DDoS attack," Facebook said in a tweet.
DownDetector.com reported Facebook had been having issues since 11:56am Eastern Daylight Time (4:56am NZ time).
During the outage social media users took to Twitter to express their frustrations - and to mock Facebook.
Among those having a bit of fun at Facebook's expense was the Canterbury Police, which issued a tongue-in-cheek tweet reminding Kiwis not to report the issue to any of its departments.
Others have complained about the outage disrupting business affairs.
"Facebook out in Alice Springs, NT, Australia. Weekly scheduled professional workshop for members worldwide won't be able to go ahead now," someone wrote.
Another person replied to that message: "Yeah they have screwed us out of a whole day profit as well. Haven't been able to communicate with customers all day."
One user stuck in a blizzard in the United States is really missing their Facebook.
"Still out in Rock Springs, Wyoming. Hell of a blizzard out and I can't scroll through my FB homepage.. this sucks."