Millions of Vodafone customers in southern England lost services when burglars smashed their way into a building and stole vital network equipment.
The raiders entered the building in Basingstoke, Hampshire, early on Monday morning and took or damaged the network and IT hardware, causing services to crash, said Vodafone.
There was a loss of voice, text and internet access across the south for millions of customers of the mobile phone giant.
A Vodafone spokesman said voice services were now up and running with text and data also due to be working soon.
"We had a break-in last night at one of our technical facilities which resulted in damage done to some of our equipment," the spokesman explained.
"This means that some customers may be experiencing temporary loss of voice, sms and internet services. We are working quickly to restore these and will be back to normal as soon as we can. There has been no impact on the privacy of customers' data."
Hampshire police officers said they were called to the property at 5am and that the raid was a targeted attack.
Detective Sergeant Lee McClellan, from Basingstoke CID, said: "We are still in the very early stages of our investigation but at this stage it appears to be a targeted attack on these premises.
"We are conducting a number of inquiries but would like to hear from anyone who may have seen a vehicle in the Houndsmill area during the early hours of Monday morning, or any vehicles stopped on the A339."