At the end of a bad week for O2, the Telefonica-owned operator has had to admit to more problems its customers are currently facing.

It appears that O2 customers abroad at the moment are experiencing a loss of service. In a statement O2 says:

"We are aware of an issue currently affecting customers who are roaming in certain countries".

"We have identified the cause of the problem and are applying a fix which we hope will restore service for these affected customers as soon as possible".

"We are very sorry for this loss of service. We will post further updates as soon as we have them".

This roaming issue follows the crash of O2's data network in the UK, leaving thousands of customers unable to send or receive emails or surf the Web this week, and a fire at a substation that brought down London cell sites.