A fire at a school which forced 350 people to be evacuated was accidental and caused by hot works being carried out on the roof, according to investigators.

The London Fire Brigade sent 35 firefighters to Cheam Common Infants’ Academy, in Balmoral Road, shortly before 1.30pm on November 2.

A spokeswoman said a small part of the school’s loft space was damaged and the fire alarm was raised within a roof void.

Around 300 pupils and 50 members of staff were evacuated “as a precaution”, however, there were no reported injuries.

Firefighters were on the scene for more than an hour as the blaze was deemed under control by 2.40pm, with crews from Mitcham, New Malden, Surbiton, and Sutton stations.

The spokeswoman added: “The fire is believed to be accidental and caused by hot works carried out on the roof.”