Hours into a global Google Talk outage that left users unable to use the instant messaging client, it appears Twitter has gone down as well.

The micro-blogging site appears to be experiencing a service disruption, with users in both Europe and the US saying they were unable to load the site.

Crowd-powered web service monitoring site Down Right Now has said there is “likely a service disruption,” based on user feedback.

Affected users are unable access the site at all - even the site’s iconic Fail Whale image is not loading for some Tweeters.

“Users may be experiencing issues accessing Twitter. Our engineers are currently working to resolve the issue,” Twitter has written on its Status page. No details beyond that have been revealed.

During an outage on 21 June, users around the world were unable to log into the service for nearly two hours. That’s believed to have been the longest-lasting crash in the social network’s history, despite its reputation for frequent, inconvenient crashes.

The timing is uncanny, given that Google Talk users affected by that disruption took to Twitter to complain en masse.

UPDATE: Twitter has apologised for the crash, citing a problem with its data centres.

"Data centers are designed to be redundant: when one system fails (as everything does at one time or another), a parallel system takes over. What was noteworthy about today's outage was the coincidental failure of two parallel systems at nearly the same time," wrote Twitter's vice president of engineering Mazen Rawashdeh in a blog post, clarifying that the outage was not caused by rabid Olympic tweeting.