Fire-ravaged Woodmill High School in Dunfermline will remain closed for at least the rest of this week.
Headteacher Sandy McIntosh has confirmed the school was extensively damaged during the blaze, which broke out at around 5pm on Sunday.
A 14-year-old boy has been charged in connection with the fire, which, at its height, was battled by more than 80 firefighters.
Mr McIntosh said he recognised the incident was “very disruptive” for families and said updates would be provided as options to accommodate pupils over the coming weeks and months were investigated.
Pupils will be given support to study at home in the meantime.
“Based on the information we have at the moment, pupils will not be able to return to school this week,” said Mr McIntosh.
“We understand this is very disruptive for families – we’re investigating all our options and will keep parents, pupils and staff updated as we progress.
“Teachers are working on ways to help pupils continue with their study from home and will be in touch soon.”
The rector said that while the fire was now out, the damage had not yet been properly assessed.
“The fire was only extinguished this morning, so we’re still at the early stages of assessing the damage, although it’s clearly extensive,” he said
“We’re looking at all our options for accommodating pupils in both the short and long term.
“I’d like to thank everyone who’s offered help and support. It’s all greatly appreciated and will help us as we consider what’s going to be best for our young people.
“We realise this is a difficult time for our families and the wider community and we’ll be putting in place a range of support in the coming days and weeks.”
Fife Council co-leaders, David Ross and David Alexander, said it was too soon to say how long the school would remain closed but insisted it was an “absolute priority” to get pupils back as soon as possible.