Twitter suffered another outage on Thursday, with many UK and US users to experience problems to access their accounts.

In a new blow to the micro-blogging service's reputation and reliability, after the popular service had gone dark for hours on June 21.

"Users may be experiencing issues accessing Twitter. Our engineers are currently working to resolve the issue," the San Francisco-based company wrote in a blog post shortly after 8:30 a.m. Pacific time (1530 GMT).

Since June's outage, Twitter claims to have significantly improved its infrastructure.