Mobile operator O2 has recommended that its U.K. customers switch off their 3G connections in order to restore 2G services, as an outage continues to affect its network.
The outage, which affected the O2 network on Wednesday afternoon and overnight, saw customers suddenly left without the ability to make or receive calls, texts, or access to data services.
Mobile virtual network operators (MVNOs) that use O2's infrastructure, including Tesco Mobile and GiffGaff, were also affected.
An O2 spokesperson told CNET sister site ZDNet that the problem was "not regional" but it was unable to confirm how many customers had been affected by the outage. O2's network is used by 23 million customers in the U.K., and media reports estimate that hundreds of thousands of them have been affected.
O2 said in a statement released on Thursday:
We are currently seeing a problem on our network affecting some of our customers. Those customers affected will have difficulty making or receiving calls, sending texts or using data.
The operator released a statement clarifying that 2G network services are now operational:
We can confirm that our 2G network service has now been restored. Customers who were affected should now be able to make and receive calls.
Our 3G service is starting to restore and customers should expect to see a gradual return of data services as the day progresses.
Customers affected may wish to try switching their mobile phones off and on as service returns. We are sorry again for the inconvenience this has caused and can provide reassurance that we continue to deploy all possible resources and will do so until full service is restored.
Telefonica-owned O2 provides mobile, landline, and broadband services to customers across the U.K.
The first signs of the outage came on Twitter at approximately 4:30 p.m. BST, when O2 said there was a problem affecting some of its customers and that its engineers were working to solve it.
However, the message appeared three hours after O2's network status page -- inaccessible at the time of writing due to heavy traffic -- said that the outage began at 1:30 p.m. BST.
A late status update from O2 said that the problem with the mobile service was due to "a fault with one of our network systems, which has meant some mobile phone numbers are not registering correctly on our network."
According to The Telegraph, customers experienced a similar outage on the network last month, and were unable to send text messages for almost a day.