The mother of one pupil told the BBC that her son was “crying because we had car trouble and it was literally breaking his heart as he was afraid about getting... suspended”.
Another parent warned the school’s rules are enforced on a blanket basis.
This means there is no clear distinction between minor infractions and more serious breaches.
“It's the way they're being enforced, there is no distinction between being two minutes late to class, literally two minutes late, and throwing a chair,” the mother said.
Pupils reportedly face suspension if they fail to complete the “reflection”.
Pupils reportedly face suspension if they fail to complete the “reflection”
Police were called to the scene but the academy’s headteacher stressed the rules were “vital” for the school’s “well-being and success”.
Headteacher Emma Haase said: “For the wellbeing and success of the whole school community it is vital that individuals' issues relating to punctuality, behaviour, uniform and organisation are kept to a minimum.
“As always, if any parents or carers have questions about how a policy is applied in a specific instance... they are encouraged to contact the academy directly.”
A spokesman for Devon & Cornwall Police said: “Officers were made aware of a protest at Camborne Science and International Academy involving pupils taking place on school grounds on Wednesday, September 20.
“Local officers attended to speak with the school to give advice on ensuring that the protest remained safe.
“This is a school matter and there are no follow-up matters for the police in relation to this.”