NHS hospitals across the UK have been hit by a large cyber attack plunging the system into chaos, and at least one hospital has been shut down.

Numerous NHS hospitals appear to have encountered a simultaneous bug in their IT systems, and emergency patients are being diverted to other areas.

According to reports the attack seems to be a form of ransomware, and is demanding money before it will return control of the systems back to the affected parties.

Several doctors have been commenting on the story on twitter and one conversation currently circulating on social media shows a Whatsapp screengrab saying: “So our hospital is down. Cyber attack was anticipated. So they’ve shut everything. You know what they show in movies.”

“We got a message saying your computers are now under their control and pay certain amount of money. And now everything is gone.”

East and North Hertfordshire Trust have also issued a statement requesting that people not come to A&E for the time being and to use either 111 or 999 if there is an emergency that needs tending to.

Jamie Moles, Principal Security Consultant at Lastline said: “The National Health Service is one of the largest organisations in the United Kingdom. With an annual budget in the region of £116 billion, it is a massive target for cyber-attacks and currently, it’s a poorly defended target”

“Interestingly, the NHS takes a very strict and sanitary approach to dealing with these attacks, shutting down almost all of its IT capabilities while it triages and treats the problem. Why would we expect any different from a medical organization? Moving forward if we are to prevent these attacks causing delays to treatment and potentially deaths, NHS trusts are going to have to invest in technology to deal with cyber-threats.”

The NHS has said that IT technicians are currently working to resolve the problem.