East Sussex County Council said half of the teaching areas had been damaged by the fire
A 14-year-old boy has been arrested after a fire partially destroyed a primary school in Eastbourne.
The blaze began at Shinewater Primary School in Milfoil Drive just after midnight. There were no injuries but damage to the school is extensive.
Fire crews from Eastbourne, Hailsham, Herstmonceux, Pevensey, Bexhill, Seaford, Hastings, Battle and Uckfeld tackled the blaze.
Sussex Police said the boy had been arrested on suspicion of arson.
The school is closed until further notice as the ground floor, first floor and roof of the building have been destroyed.
Richard Fowler, from East Sussex Fire and Rescue Service, said: "The investigators will be looking closely at the scene today, looking at the evidence and trying to establish what the cause of the fire was."
Police have asked if anyone heard or saw anything suspicious around the area
Parent Peter George Allen witnessed the fire. Writing on Facebook, he said: "The head teacher had just walked past us and looked to be in tears.
"Cannot believe what I am watching here and it's a horrible feeling having to tell Francesca tomorrow."
Head teacher Theresa Buttery said: "We've lost about 50% of our teaching space. All our year three, four, five and six classrooms are affected by this.
"Our focus now is to ensure we can get the younger children back into the non-damaged areas of the school as quickly as possible and find alternative provision for the older children."
'Upsetting for everyone'
Stuart Gallimore, East Sussex County Council director of children's services, said the school and council were working together to find alternative provision for the pupils as quickly as possible.
"However, our first priority has to be the safety of the children," he added.
"This has been an upsetting incident for everyone concerned with the school, but we're thankful that no-one has been hurt and we'd like to thank the fire service who have worked through the night to tackle the blaze and its aftermath.
"We will continue to keep parents informed of the situation as it develops in the coming days," he said.
Local MP Caroline Ansell said: "The town is rallying, there have been offers from local churches and other schools and we will make that provision."
Alternative accommodation is to be found for pupils
Families gathered at the school gate with many children expecting to go on a school trip
The ground floor, first floor and roof of the building have been destroyed, the fire service said
