LONDON: British hospitals said they were forced to divert emergencies on Friday (May 12) after a suspected national cyber attack.
"We are aware of a cyber security incident and we are working on a response," said a spokesman for NHS Digital, a division of the NHS which handles information technology issues.
The National Health Service said that as of 3.30pm local time 16 organisations had reported that they were affected by the cyber attack.
In a statement, it said it believed the malware variant used in the attack was called Wanna Decryptor.
It added that the attack was not specifically targeted at the NHS, and was affecting organisations from across a range of sectors.
"At this stage we do not have any evidence that patient data has been accessed. We will continue to work with affected organisations to confirm this," it said in a statement.
"NHS Digital is working closely with the National Cyber Security Centre, the Department of Health and NHS England to support affected organisations and to recommend appropriate mitigations," it added.
British hospital workers were warned on Friday that they were at threat from malicious software, according to an email seen by Reuters.
"The Trust has been advised by I.T. security and NHS-Digital of a serious Ransomware threat currently in circulation throughout the NHS," the email to employees of Britain's National Health Service said.
"Following a suspected national cyber attack we are taking all precautionary measures possible to protect our local NHS systems and services," NHS Merseyside in the north of England said on Twitter.
Patients requiring emergency treatment across England were diverted from the affected hospitals and the public was advised to seek medical care only for acute medical conditions.
"We are experiencing a major IT disruption and there are delays at all of our hospitals," said Barts Health, England's largest NHS hospital trust, in a statement on its website.
"We have activated our major incident plan to make sure we can maintain the safety and welfare of patients. We are very sorry that we have to cancel routine appointments, and would ask members of the public to use other NHS services wherever possible."
It added that ambulances were being diverted to neighbouring hospitals, and that the problem was affecting the switchboard at Newham hospital, but that direct line phones were still working.
A reporter from the Health Service Journal said the attack had affected X-ray imaging systems, pathology test results, phone systems and patient administration systems.
Local media reported that the hack appeared to involve ransomware, with the Independent citing online messages saying that hospitals were being told they would have to pay a ransom to regain control.
"We got a message saying your computers are now under their control and pay a certain amount of money," the Independent reported the messages as reading. "And now everything is gone.”
Britain's National Crime Agency said it was aware of the reports of a cyber attack but made no further comment.
The opposition Labour Party said the government "needs to be clear about what had happened, and what measures they are taking to reduce the threat to patients".
"This cyber attack is terrible news and a real worry for patients," said Shadow Health Secretary Jonathan Ashworth in a statement.
“The safety of the public must be the priority and the NHS should be given every resource to bring the situation under control as soon as possible.“
Earlier on Friday, Spain's government warned that a large number of companies had come under a similar ransomware attack.
Researchers behind the MalwareHunterTeam Twitter account noted that the ransomware had also infected users in countries including Russia, Germany, Japan, Indonesia, Vietnam, and the Philippines.