Visitors to the website were greeted by a message telling them that "Something is technically wrong".
"Thanks for noticing," the message reads. "We're going to fix it up and have things back to normal soon."
Mobile apps as well as the website itself appeared to be broken. Tweetdeck, Twitter's other official client, was also broken.
Twitter's @Support account posted a message saying that "Some users are currently experiencing problems accessing Twitter. We are aware of the issue and are working towards a resolution." (That account is itself part of the outage, but Twitter sent the text of the tweet to The Independent.)
Twitter's official status page didn't show any information about the outage, at the time of publishing, though it is often slow to update. But the Down Detector website showed a huge spike in reports on Tuesday morning UK time.Last modified on Tuesday, 19 January 2016