Hacker groups have jumped to claim credit for several outages to social network Twitter overnight, which downed the service for its 614 million accounts worldwide.
Twitter confirmed the outages on its status blog but did not explain what caused caused the intermittent problems.
A “hacker group” named UGNazi was quick to claim credit for the outages – on Twitter – but there has been no confirmation of its involvement.
Uptime monitoring site Pingdom noted three outages to the microblogging site, with the longest one lasting over an hour.
Twitter’s PR team this morning tweeted that the overnight outage was “due to a cascaded bug in one of our infrastructure components” and promised further information later.
Today's outage is due to a cascaded bug in one of our infrastructure components. We'll provide updated information soon.— Twitter Comms (@twittercomms) June 21, 2012
Twitter has a chequered reliability history, with the site experiencing frequent crashes over the past years.
The outages come as Twitter is planning to push ads out to fifty countries, hoping to earn more than a quarter billion dollars from the move.
However, of late, the site's users haven't seen much of Twitter's "Fail Whale", an icon displayed when something goes wrong with the network. Pingdom reported average monthly uptimes for the network of between 99.62 and 100 percent.