In a statement on Cwmcarn High School's website, headteacher Jacqui Peplinski said "concerns were dealt with swiftly".
"There was no risk to any staff or learner and the relevant support services were contacted as a precautionary measure."
"Cwmcarn High is a caring and safe environment and we are committed to everyone’s safety."
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High pressure will remain in charge bringing another dry day, with more sunshine than yesterday.
A cloudy night to come with the odd spot of light rain. Saturday will be fine and dry with sunny spells throughout the day.