A FIRE at a York school is now believed to be arson, after CCTV images showed a man acting suspiciously on the site at the time of the blaze.

The fire at All Saints' School, Mill Mount Lane, York, on Tuesday evening was first thought to have been started by a faulty extractor fan.

But that theory was quickly ruled out by fire service investigators.

Divisional Officer Graham Buckle said: "We have got some CCTV footage of a man in the area at the time of the fire, and when we had a look at the burn patterns in the light of day we were able to rule out the fan as the cause of the fire."

Police today confirmed that they were treating the fire as suspicious.

David Aked, health and safety advisor for education and leisure at City of York Council, said he realised the fire may have been deliberate when he saw a piece of stone that was found in the room where the fire started.

Mr Aked said: "We do have some video evidence of a person acting suspiciously."

Mr Aked said fire crews arrived shortly before 8pm. Smoke could be seen on CCTV footage from about 7.35pm.

The man on the CCTV footage, who had dark, receding hair and was wearing a light-coloured T-shirt and shorts, black socks and footwear, was seen on the school site between 7.15pm and 7.45pm.

The fire, which caused more than £5,000 damage, started in a detached art block.

The roof and store room were severely damaged. The classrooms were damged by smoke and water.

Mr Aked said the school, which has a public right of way running through it, was targeted by arsonists in 2001, which led to increased security measures, including more CCTV coverage.

Updated: 10:43 Thursday, August 07, 2003