Firecrews were called out after a blaze erupted at Mayday hospital in Croydon Ian Stratton

PATIENTS at a major London hospital were evacuated today after a fire broke out in a suspected arson attack.

The blaze erupted in the early hours of this morning at a hi-tech unit in Mayday hospital.

Fire crews arrived within minutes at hospital’s magnetic resonance imaging (MRI) suite at the hospital in Croydon, south London, after the alarm was raised and staff called 999 just after 3.30am today.

A "major incident plan" was put into action by hospital bosses, and patients were moved to another wing of the building. No one was injured.

Firefighters wearing breathing apparatus got the blaze under control in five hours. They said 50 per cent of the first floor was damaged.

The MRI unit - used to help physicians diagnose and treat various medical conditions - is a stand-alone building next to the hospital and no patients were in the wing at the time. The 30 patients were in neighbouring wards and moved to a safer area.

A three-storey building which is also part of the hospital suffered smoke damage.

Today the hospital said planned surgeries and appointments had been cancelled.

A spokeswoman for Mayday Healthcare NHS Trust - which is responsible for the hospital - said: "Mayday is working closely with its partners at the London Ambulance service, fire brigade, police and primary care trust to manage the incident.

"As a precaution all routine planned surgery and all out-patient appointments in the London wing have been cancelled today. A decision will be made over the course of the day as to when these services can resume."

A London Fire Brigade spokesman said: "Eight fire engines and around 40 firefighters were called to a fire at a hospital on Mayday Road, Thornton Heath.

"The fire damaged a small amount of the ground floor and part of a medical unit was also damaged by the blaze.

"The Brigade was called at 3.36am and the fire was under control by 8.24am.

"Fire crews from Norbury, Croydon, West Norwood and Woodside fire stations attended the incident. The cause of the blaze is under investigation."

A Met police spokesman said the fire was being treated as "suspicious". He added: "Officers from Croydon were called to the scene and are carrying out an investigation."