An investigation has been launched after a suspected arson attack resulted in about 700 pupils being evacuated from a burning school.

The blaze broke out at Wyke Manor Upper School, in Wilson Road, Wyke, at about 1.50pm today.

A rubbish fire outside the school, suspected to have been started deliberately, quickly spread to the side of the science block. The blaze resulted in heavy smoke-logging of a major part of the school and the children had to be sent home for the day.

Simon Moore, watch manager at Odsal fire station, said: "Apparently, there were some kids in that area at the time that a small rubbish started fire outside the school, which spread to one of the buildings. We are treating it as potentially deliberate.

"The fire got into the 6inch gap between the outside cladding on the building and the building itself. We had to rip off the cladding to get to it, but we soon had it under control. About 700 pupils and staff were evacuated from the building, but there were no injuries."

Mr Moore said the school had launched an internal investigation into the cause of the blaze and would be working alongside West Yorkshire Police to get to the bottom of the incident.

A police spokesman said: "It is being investigated as a suspected arson. Inquiries are ongoing."

Two fire engines from Odsal attended the scene and firefighters spent an hour and a half fighting the flames and using positive pressure fans to clear the smoke from inside the building.