Twitter network down for many users after technical fault
Social network Twitter is offline for many users, with web visitors being greeted by an error page.
Some mobile users are also unable to read or post tweets to the network, which has over 300 million active members.
Twitter chose to communicate the problem via a tweet, in which the firm said it was aware of the problem.
Some users took to Facebook to complain.
A spokesman for Twitter said that a tweet from the company's @support account read: "Some users are currently experiencing problems accessing Twitter. We are aware of the issue and are working towards a resolution."
The issue began shortly after 0800 GMT, according to Down Detector.
For some, the site appears to be intermittently accessible while the issue persists.