Fire has broken out at Roding Primary School in Dagenham, east London.
Some 80 firefighters are tackling the blaze in Hewett Road, London Fire Brigade (LFB) said.
A total of 12 fire crews were called to the fire at 4.50am and about half of the single-storey building was alight at 6.30am.
Crews from Dagenham, Ilford and Barking stations were among those scrambled.
They have removed a gas cylinder from the building, LFB said, “and are cooling it to ambient temperature as cylinders can explode when exposed to heat”.
The cause of the fire is not yet known, the brigade added.
Children had been due to return for the start of the autumn term on Wednesday, according to the school’s website.
Phones and email went down across both the school’s sites, it said, with the Hewett Road location now closed for at least two days.
Pupils in Years 1 to 6 should attend the Cannington Road site, it added.
The neighbouring Saint Teresa Catholic Primary School is also closed on Tuesday due to the fire. Administrators said they hoped to re-Wednesday.
The Independent has contacted Barking and Dagenham council for comment.
