Mobile network operator O2 has said it is launching a “full investigation” after people across the UK lost signal to their phones yesterday.
The company apologised after people in areas including London, Manchester, Bristol, Glasgow and parts of Northern Ireland lost reception – some for up to five hours.
Business Secretary Sajid Javid was among the disgruntled customers who took to Twitter to express their frustration and told the company to “sort it out”.
Normal service was restored shortly after midnight last night and the provider said it would be trying to identify the source of the disruption, while it was still unclear what has caused the issue.
O2 said in a statement: “Further to our previous messages where some customers experienced some problems accessing our network, we can confirm that service returned to normal at 23.35 yesterday.
“We apologise for any inconvenience caused to those customers affected and we will now begin a full investigation to identify the root cause.”
Customers were advised to switch their phones on and off if they were still experiencing difficulties, as O2 apologised to people on Twitter.
But many O2 customers had taken to social media saying they weren’t able to send or receive calls and text messages, as well as problems with the 3G internet signal.
O2 said it was monitoring the situation and was working with its suppliers to investigate how the signal failure occurred.