A virulent computer virus is causing mayhem at three major London hospitals.

The virus has already defeated It staff at St Bartholomew's, The Royal London and the London Chest Hospital after striking on Monday, and now the computer systems have had to be shut down.

The hospitals' management teams are now having to divert patients elsewhere for treatment.

The hospitals remain open to walk in patients but staff are now using a manual system of records keeping and admission tracking, so are seriously slowed down.

Operating theatres and outpatients departments are still "operational" though said an NHS Trust spokesperson.

The virus is thought to be the Mytob strain, which is a Trojan that is spread by email and then affects Windows operating systems.