A Cambridge high school that was hit by fire Tuesday will reopen next Monday.

Waterloo Region District School Board officials tell CTV News classes will take place at Southwood Secondary School as normal, although a section of the school will remain closed for police investigation.

The fire is considered suspicious, although an exact cause has not been determined.

Officials say it started in a second-floor washroom and was contained to the washroom area, but smoke damage extended to more of the floor.

Students were evacuated when the fire started Tuesday afternoon, and classes were cancelled for the rest of the week.

Students were allowed back into the school Friday afternoon to take items from lockers and classrooms on the first floor, but not the second floor, which remained cordoned off for the fire investigation.