Thousands of appointments, transplant operations, cancer referrals and C-section procedures have been cancelled as a result of the Russian cyber attack on London NHS hospitals, it has been revealed.
The NHS declared a 'critical incident' after hackers hit London hospitals on Monday, affecting Guy's and St Thomas' (GSTT) and King's College Hospital Trusts.
Now it has emerged more than 200 emergency and life-saving operations had to be cancelled at those hospitals, The Independent reports.
Additionally, more than a third of procedures and operations were halted, including more than 3,000 non-surgical appointments.
People who had been referred for urgent cancer diagnosis, mothers awaiting C-sections, patients awaiting transplants and blood transfusions have also been affected.
Thousands of appointments, transplant operations, cancer referrals and c-section procedures have been cancelled as a result of the Russian cyber attack on London NHS hospitals, it has been revealed (stock image)
More than 200 emergency and life-saving operations and more than a third of procedures and operations were halted, including more than 3,000 non-surgical appointments, following the cyber attack on Monday (file pic)
It is understood IT system Synnovis, which serves NHS pathology labs and runs tens of thousands of tests a day, was the target of the attack.
The system is run by SYNLAB UK & Ireland and performs more than 32 million pathology tests a year.
Synnovis says it serves 1.7 million people in southeast London each year as it collaborates with the two affected NHS hospital trusts.
Alongside GSTT and King's College, mental health and community care provider South London and Maudsley NHS trust was impacted by the cyber attack.
Earlier this week, it was reported that the Royal Brompton and Harefield had to cancel potentially life-saving transplant operations, with Evelina London Children's Hospital also affected.
GP surgeries across six London boroughs also reported problems in Bexley, Greenwich, Lewisham, Bromley, Southwark and Lambeth.
It is unclear whether the hackers, believed to be from Russian cyber-crime group Qilin, have infiltrated patient data.
An NHS London spokesperson said: 'NHS staff are working around the clock to minimise the significant disruption to patient care following the ransomware cyber-attack and we are sorry to all those who have been impacted.
'Pathology services are integral to a wide range of treatments and we know that a number of operations and appointments have been cancelled due to this attack.
'We are still working with hospitals and local GP services to fully assess the disruption, and ensure the data is accurate.'
Guy's and St Thomas and King's College hospital trusts, South London and Maudsley NHS trust, the Royal Brompton, Harefield, Evelina London Children's Hospital and GP surgeries across six London boroughs were all affected by the cyber attack
Patients have been advised to continue attending their appointments unless they have been contacted directly by the hospitals affected.
Sources told The Independent the impact on NHS services could last for months, although the most urgent and priority services could be restored in weeks.
The National Cyber Security Centre (NCSC) is involved in managing the situation alongside the NHS and the Department of Health and Social Care.