document: South Wales Fire and Rescue Service was called to St David's Junior and Infants School, Cwmbran, at about 20:10 BST on Saturday.
  The fire started in an outdoor storage container and spread to a ground-floor classroom, causing minor damage.
  Additional security has been put in place until the school reopens on Tuesday.
summary: A suspicious fire which has damaged a classroom at a school in Torfaen is under investigation.