Facebook, Instagram and Whatsapp were partially down for some users around the world Wednesday.
In response, users took to Twitter -- and the hashtags #facebookdown and #Instagramdown became top trending topics, USA Today reported.
Though it is unclear what caused the outage, Facebook, which owns Instagram and messaging app Whatsapp, acknowledged the interruption on Twitter.
The company also promised it was working to resolve the issue, which it said was not related to a distributed denial-of-service (DDoS) attack.
A DDoS attack happens when hackers have “brought down” a website, according to Norton.
Downdetector, a website where users can report their problems with other sites and apps, started receiving complaints around noon ET and peaked at 11,000 worldwide outages.
The outages were reported in the U.S. on the East and West Coasts, as well as in parts of Europe and in other parts of the world, according to Downdetector.
By about 5 p.m., most issues had been resolved.
Over the course of several hours, while the site was having issues, there were a variety of problems reported, according to CNBC, including not being able to load Facebook or not being able to post comments.