O2 down: 4G still not working and company does not know when it will come back online amid data chaos

Network has not been working for more than 12 hours

O2's data network has been offline for more than 12 hours and nobody appears to have any idea when it will come back online.

Both the network itself as well as Ericsson – whose software appears to be to blame for the problems – has repeatedly committed to bring the data service back online as soon as they can.

But neither has offered a specific timeline for when the fix will be in place, or any real detail of whether it is close to fixing it.

The network's chief executive, Mark Evans, gave the latest statement on the ongoing outage. But he failed to give any detail on the problem itself.

"I want to reassure our customers that we are doing everything we can to fix the issue with our network and say how sorry I am to everyone affected," he tweeted. "My teams are working really hard with Ericsson to find a swift resolution."

The problems appeared to begin around 5am UK time, as data connections went offline without any notification. They have been that way ever since, apparently affecting not only every O2 customer but also customers of those networks that rely on its infrastructure, such as GiffGaff and Tesco Mobile.

Ericsson said the issues had not only affected O2 customers in the UK but networks globally, including Japan's Softbank. But it also gave no prediction of when it could be back online.

"The faulty software that has caused these issues is being decommissioned and we apologise not only to our customers but also to their customers," said its president, President Börje Ekholm. "We work hard to ensure that our customers can limit the impact and restore their services as soon as possible."