A major outage has left O2 customers with problems using data and making calls.
As many as two million people — one in 10 of the network's 22.4 million customers — are thought to have been affected since the network started experiencing issues as early as 10:27am on Friday.
Customers took to social media sites such as Twitter to complain about the lack of service.
Sarah Milne tweeted: "@O2 I have absolutely nothing. No signal, no 3G and just beeps if anyone tries to call. Any ideas when it will be fixed?"
According to the network, the issues should be resolved before too long. "Approximately 10 percent of our customers have experienced intermittent service when making calls or using data since lunchtime today. Some customers will already have had their service restored and we will have a full fix this afternoon. We are sorry for the inconvenience this has caused those customers," O2 said in a statement.
O2 suffered an outage in July that affected thousands of its users across the country, leaving them without access to voice, data or text services for over a day. The operator later offered compensation for the disruption, giving contract customers 10 percent off their September bill — equivalent to three days' free service.