Users across Facebook, Instagram and WhatsApp have reported issues with parts of the social media giant's suite of apps.
Many took to rival platform Twitter to highlight the problem, which seems to be preventing images and videos from loading properly.
Facebook said it was working to resolve the error as #instagramdown began to climb up the trending list on Twitter.
On WhatsApp, some users noticed image and video files were not able to send, while others on Instagram claimed they could not see images on their feed.
"We're aware that some people are currently having trouble uploading images, videos and other files on our apps," a spokeswoman for Facebook said.
"We're working to get things back to normal as quickly as possible."
Facebook has more than 2.3 billion monthly active users and Instagram has one billion.
