LONDON (AP) - Twitter says the issue that caused problems for users today has been resolved.
It isn't saying what the issue was.
For more than an hour today, users in many parts of the world reported outages and sluggishness.
Visitors to the micro-blogging site were greeted with a half-formed message saying that "Twitter is currently down." The fields where a reason for the outage and a deadline for restoring service were apparently meant to go were filled with computer code.
The problems affected parts of the Americas, Europe, Asia and Africa.
Some users were able to post updates through their phones or third-party applications. Tweets about the Olympic torch making its way through central London poured in, but slowly.
While the site was affected, many self-proclaimed "Twitter refugees" posted complaints about Twitter on Facebook.
The breakdown came only hours before the Olympics are expected to bring an unprecedented surge of activity by sports fans on Twitter and other social networking sites.
It was the second time in just over a month that the site has been hit by problems.