POLICE yesterday said a massive inferno which devastated a school was started deliberately.

Following inquiries by police officers and fire service investigators the blaze at the west Dunbartonshire school is being treated as wilful, they said.

Education chiefs met yesterday at the site of Vale of Leven Academy in Alexandria and decided to keep the school closed until after the summer holidays.

Det Sgt Jim Bradley, who is leading the police investigation, said: ''I would urge anyone, particularly private hire taxi drivers, who may have been in the area at the time and who may have witnessed anyone acting in a suspicious manner, to come forward.''

Millions of pounds worth of damage was caused after a ferocious blaze ripped through the school's annexe building at around 12.40am on Saturday.

The school's library, computer suite, games hall, cafeteria and 28 classrooms were all destroyed by the fire. Around 50 firefighters battled for six hours to finally bring it under control. There were no casualties.

Although the school will remain shut until August, school trips to Germany, Alton Towers and the West Highland Way, arranged for this week, will still go ahead.

Vale of Leven Academy has 1,187 pupils. The school building was erected in the 1960s, with the annexe being added in 1970.

The annexe contained classrooms for teaching English, modern studies and physics. Three computer suites and four business studies suites were only added a few years ago

Headteacher Terry Lanagan told of his shock to hear that police suspected the blaze was a case of fire-raising and appealed for witnesses to come forward.

He said: ''It's even more distressing to learn that the fire was started deliberately. I find it shocking that anyone would purposefully destroy a school building and thereby cause such distress to so many pupils, parents and staff. I would encourage anyone with information which may identify the culprit or culprits to get in touch with the police.''