Part of a Watson primary school was damaged by a fire on Monday night, in what police believe was a suspicious blaze.
The building at Majura Primary school was set alight just after 9.30pm on Monday.
Fire crews and police were called to the scene and the blaze was brought under control.
An ACT Policing spokesman said after forensic analysis at the scene, the fire was being treated as suspicious.
Police are appealing for anyone who witnessed the incident, or anyone acting suspiciously near the school on Monday night, to come forward.
Anyone with information is urged to contact CrimeStoppers on 1800 33 000.