Facebook Messenger has suffered a major outage, leaving users unable to send or receive messages.
It is one of several Facebook apps to experience difficulties, with both the main Facebook app and Facebook-owned Instagram also going down.
It is not yet clear what caused the issue, though it is the latest in a series of significant outages for the social media giant.
According to website monitor Down Detector, users all over the world are affected.
It is understood that all three apps share the same underlying infrastructure, meaning problems are often shared across all platforms.
In March, Facebook, Instagram and Facebook Messenger all stopped working for nearly an entire day, in what is thought to be the biggest outage in the company's history.
Another significant outage took place in July, lasting around 12 hours. The reason for the outage was not revealed, with Facebook blaming a "server configuration change".
It is difficult to know how long users can expect to have issues with the services, as Facebook typically chooses to not be transparent about outages.
Facebook did not immediately respond to a request for comment.
