Thousands of O2 mobile phone users have been left unable to access the internet because of a technical fault.
The mobile network said it had set up an urgent investigation after customers reported being able to get online or use mobile date from the early hours of Thursday.
Engineers are working to fix the problem.
“We are aware our customers are unable to use data this morning,” the company said on its official Twitter account.
“Our technical teams are working on the issue with high priority. We are really sorry and working as hard and as fast as we can to fix this.”
The service status page of the O2 website added that “voice calls are working OK” and apologised for any inconvenience caused.
Other mobile networks, including Sky, Tesco and Giffgaff have also been affected by the problem because their networks use O2 services.
O2 said it would share further updates as soon as they were available.
More to follow…