Children's work and toys were badly damaged in a portable building

The blaze began at the nursery section of Croes Atti School in Flint - also home to a Welsh-medium nursery - just after midnight on Saturday.

An investigation is underway into the cause of a fire which caused extensive damage to the school.

The exact cause of the fire is being investigated by the fire service and North Wales Police.

Fire safety enforcement officer Stuart Millington said the vandals such as these were diverting "life-saving" resources.

Mr Millington said: "The trend of deliberate fire is worrying for North Wales Fire and Rescue Service as resources become committed that could be required at other life-saving incidents.

"Not only is that type of incident a drain on physical resources, but it also results in a significant financial burden for the local community.

"It is terrible to see such a mindless act of vandalism resulting in the loss of the children's hard work and creating severe disruption to their education."

The fire caused extensive damage to a portable building on the school site and the children's work and toys inside.

It is used by the Welsh-language Cylch Meithrin playgroup and discussions have been hold on how to accommodate the children.