A message on Twitter's Web page that provides updates on the service's status said: "We've temporarily disabled #NewTwitter. Our engineers are working on re-enabling it and we'll update you shortly."

Twitter, which allows users to send short, 140-character messages to groups of "followers," has more than 200 million registered accounts and has become a popular communications service with businesses, celebrities and protesters in the Middle East.

Last month Twitter announced that it had moved its infrastructure to a new home at an undisclosed location, which the company said would allow it to constantly "stay abreast" of its capacity needs and provide greater reliability.

More: http://www.reuters.com/article/2011/04/06/us-twitter-idUSTRE73503420110406