Millions of smartphone users in the UK have lost their data services after the O2 network suffered technical problems.
O2 has 25 million customers, but also provides services for the Sky, Tesco, Giffgaff and Lycamobile networks which have another seven million users.
O2 blamed the problem on a supplier and Ericsson, which makes mobile network equipment, said it was working to solve the issue.
Japan’s Y!Mobile network, owned by Softbank, also suffered big problems.
O2 said: “We believe other mobile operators around the world are also affected. Our technical teams are working with their teams to ensure this is fixed as quickly as possible.
“We’d encourage our customers to use wi-fi wherever they can and we apologise for the inconvenience caused.”
The difficulties in the UK were first reported at about 05:30 on Thursday.