Two schools have been damaged by fire within the same number of weeks.
Castleford Park Junior Academy suffered damage to its Leake Street entrance after a blaze broke out on Tuesday.
A West Yorkshire Fire and Rescue spokeswoman said: “It was a fire involving the roof of a single story extension.
“Four fire engines attended from Castleford, Wakefield, Normanton and Garforth.
“Nobody was hurt. The school was closed for the holidays.”
But black smoke could be seen billowing from the school, which crews dampened down after the fire was put out after just more than an hour.
The school could not be contacted for a comment, but it tweeted: “There has been fire damage to school at Leake Street entrance.
“It has been contained and everyone is safe.”
An investigation into the cause is taking place.
And the race is still on to open Airedale Junior School before September.
Eight fire crews tackled a blaze at the Fryston Road school after being called out on July 14.
Michaela Blackledge, chief executive officer of Airedale Academies Trust, which runs the school, said teams will be working over the summer break to ensure the school will be open as normal in September. The cause of the fire was accidental, she said.