Arson suspected in Victorian high school fire overnight

Police believe a fierce fire which destroyed half of a secondary school in Victoria early this morning could have been started deliberately.

In video obtained by 9NEWS, huge flames and plumes of black smoke can be seen emanating from the school's science building.

Country Fire Authorities were called to Daylesford Secondary College at 3.20am after a fire broke out in the north wing of the Smith Street Campus.

A spokesperson for the CFA said it took firefighters two hours to bring the fire under control, with the extent of the damage contained to one wing.

Between 14 and 15 fire trucks battled to contain the fire at its peak.

The CFA issued an advice warning to residents amid fears the fire would spread to grassfires.

Police believe the fire was deliberately lit, with the alleged arsonists breaking into the northern wing just after 3am.

Fire crews remain on the scene as detectives and arson chemists investigate the fire.

Anyone with information is urged to contact Crime Stoppers on 1800 333 000.