LONDON (dpa-AFX) - The British National Health Service (NHS) is urgently appealing for blood donations following a cyber attack on several hospitals. The attack, which is believed to have been carried out by a Russian hacker group, means that patients' blood groups cannot be tested as quickly as usual, it said in a statement on Monday.

The NHS therefore urgently called for donations of blood groups 0 negative and 0 positive. People with blood group 0 negative are considered universal donors. Their blood can be administered to all patients and is therefore particularly in demand in emergencies when there is no time to carry out a test. 0 positive is the most common blood group and is therefore also in demand.

"Patient safety is our absolute priority. If hospitals do not know a patient's blood group or do not have it available, it is safe to use group 0 blood," said NHSBT Medical Director Gail Miflin.

The hackers are said to be after money

Last week's ransomware cyberattack affected several major hospitals in London, including King's College Hospital, St. Thomas' Hospital and Evelina London Children's Hospital. Specifically, the Synlab subsidiary Synnovis, which carries out laboratory tests for the hospitals, was attacked.

According to the authorities, the Russian hacker group Qilin is behind the attack and is said to be after money. In attacks using so-called ransomware, data is encrypted and a ransom is demanded for its release./cmy/DP/ngu