Mobile phone operator O2 has apologised to customers after its data network was down across the UK on Thursday morning.
O2, owned by Telefonica, is investigating reports of issues with 3G and 4G data, leaving customers without internet access.
Problems were first reported at around 5.30am with about 1,662 complaints made before 7 am about outages in London, Birmingham, Manchester, Glasgow, Leeds and other UK areas, according to the Downdetector website that tracks internet service issues.
Other mobile phone providers that share the O2 network, including GiffGaff and Mobile, were also affected. Transport for London's electronic bus timetable was also hit by the problem.
O2 said calls were still working but data connections were broken.
“We apologise for any inconvenience,” the firm said.
I can’t use my phone for Anything no data no calls no texts ????— Amy-Lou Hudson (@MissLou86) 6 December 2018
Ernest Doku, mobiles expert at uSwitch.com, said the issue with O2 was worrying for some 32 million UK customers.
"For the millions of users who are out and about and rely on smartphone maps to get around, it's worth considering that apps like Google Maps allow customers to download maps on WIFI and view them offline,” he suggested.
"With little idea of when this problem will be sorted, it's worth preparing before heading out to make sure you're not caught out by this data downtime."