PATIENTS were evacuated from a hospital last night after a suspected arson attack which caused £30,000 of damage.

Firefighters said the blaze at around 7.30pm was started in Queens Park Hospital, Blackburn.

Someone set fire to a pile of washing stacked up in a second floor room of the mental health unit for the elderly.

Police were today questioning a man in connection with the blaze, which they said was being treated as arson.

The 16 evacuated patients were transferred to a facility in Accrington.

One room was 50 per cent damaged by fire and the rest of the floor was heavily smoke logged.

The fire also spread into part of the roof.

Phil Hesketh, service director of mental health, said hew hoped the ward would be reopened in a week.

"The important thing is that staff equipped themselves fantastically. The patients' safety was obviously paramount and staff followed guidelines to keep any disruption to a minimum."

Sub-Officer Eric Trotter said : "We got the automatic fire alarm at 7.40pm. When we arrived we could see smoke and flames out of the top floor of the unit.

"When we entered all the patients of that floor where already evacuated to the main staircase. The hospital's fire teams had responded to the alarm and evacuated the patients.

"The ward itself is divided into various smaller wards through a central corridor.

"Half way along the floor there was some double fire resistant doors and that was as far as the smoke had gone.

"It was a dense black smoke and we had to send in officers with breathing apparatus to find the fire, the smoke was that bad. Once it was discovered four officers were sent in. It was in a room which is used for storage.

"A pile of clothing stacked up in bags had been set alight. The fire had spread into the roof."

A police spokesman said: "We are treating the fire as arson. It caused around £30,000 of damage.

"One man has been arrested and is being held in custody."