Two ambulance trusts have been left without access to electronic patient records after a cyber attack.

South Central Ambulance Service (SCAS) and South Western Ambulance Service (SWASFT), which serve a population of 12 million people, are both affected.

The attack targeted a third-party technology company used by the trusts.

NHS England has confirmed it is investigating the incident alongside the police, and work is ongoing to reconnect the system.

South Central Ambulance Service Trust attends incidents in Oxfordshire, Berkshire, Hampshire and Buckinghamshire, along with non-emergency coverage for Sussex and Surrey.

South Western Ambulance Service Foundation Trust covers Bristol, Cornwall, Devon, Dorset, Gloucestershire, Somerset, Wiltshire and the Isles of Scilly.

The service lost access to its electronic patient records on 18 July, according to the Health Service Journal's ambulance correspondent Alison Moore.

"This was due to a cyber attack which affected the supplier – a Swedish firm called Ortivus," she said.

Ms Moore said patients were not being affected directly, but ambulances were turning up without their usual levels of medical history, such as allergies, significant health incidents and medications.

She added she was sure the standard of care was still "very high" but that incidents might be taking longer to deal with.

"Crews are on the road without important information about the people they've been called to see," she said.

An NHS spokesperson said: "We are aware of an incident affecting a small number of ambulance services.

"Our Cyber Security Operations Centre is working with affected organisations to investigate, alongside law enforcement colleagues."

The 999 call system is not affected and people can still contact the ambulance services as normal.

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