A derelict school which has been plagued by vandals since it closed in February is suspected of having been set alight yet again.

Two youths have been arrested following the blaze which tore through the roof at the Guardhouse School building in Keighley.

Firefighters suspected boobytraps had been set in the building – such as lifted floorboards – so the crew fought the blaze from outside taking two hours to bring it under control.

Wednesday’s fire follows calls by people in the area for the building to be razed to the ground as it has been a magnet for youths who have broken in and used it as a drinking den.

Nearby residents say youngsters are regularly seen on the roof.

Father-of-two Phil Miller, who lives in Braithwaite Way, watched the firefighters tackle the latest blaze.

He said: “It’s been on fire at least eight times since the school closed in February, but this was the biggest by far. The flames went right through and the roof came down.’’ A neighbour, who did not want to be named, said: “The place is dangerous and should be demolished.”

Police said two youths had been arrested and released on police bail as inquiries continue.

A Bradford Council spokesman said work to demolish the site is due to start next Wednesday. Pupils and staff moved out of the building last February into the newly-built Merlin Top Primary School nearby.