Atmosphere during a 4D projection at the launch of EE, Britain's first 4G mobile network at Battersea Power station on November 1, 2012 in London, England / Tim Whitby/Getty Images

The company has said that it is aware of the problems and is working on a fix

Mobile network EE is being hit by problems that are leaving people unable to make calls to landlines.

The company has said that it is aware of the problem and is looking to work on a fix. It also said that the problems were affecting networks other than EE.

“We can confirm we’re aware customers from EE (and other networks) are having issues calling landlines," a spokesperson said. "We’re investigating urgently.”

The EE Twitter account has spent much of the time since the network went down replying to customers on Twitter.

"We are aware of an issue and this is a priority one for us," one characteristic tweet reads. "Our team are currently investigating and we're hoping to have it up and running again shortly.

"Apologies for the inconvenience."

EE was formed in 2010, when the brands known as T-Mobile and Orange were added together and took their customers with them. It is being bought by BT in a deal that is expected to go through in 2016.