Twitter Inc. says users are experiencing problems accessing its microblogging service

Social media site Twitter was sporadically down across much of Europe and portions of the USA early Tuesday.

Both Twitter web and mobile services suffered outages for at least an hour around 0900 GMT, with smartphone users receiving the warning: “Tweets aren’t loading right now”.

A spokesperson for Twitter Europe confirmed the outage, without detailing how widespread it was and how long it would last.

There was no immediate way to determine whether full service had been restored for all users.

A Twitter spokeswoman said that the company will continue to post updates on its blog, but declined to elaborate on the cause behind the outage. An update at 1 p.m. said the issue had been resolved. But problems lingered; those in our USA office had trouble posting tweets via Twitter.com around 9:30 a.m. ET; an error message blamed server issues.

Twitter was unavailable for users worldwide, with the site apparently suffering wo patchy a total outage.

Third-party services, such as TweetDeck, seemed to be working in the US, but were reportedly delayed or inaccessible elsewhere.

Twitter’s API and Tumblr status pages reveal that this outage may be part of a larger issue, though the API page claims service is back to normal at this time.

According to the Daily Mail, some users have had success accessing the service using Twitter’s mobile apps.

Users from Scandinavia to Saudi Arabia to South Africa reported outages. Meanwhile, the company’s stock continues to languish at an all-time low.

In morning trading Tuesday, Twitter shares fell 35 cents to $17.59.