A knife was found on a student after a fight broke out between a group of pupils.
Police were called to Lightcliffe Academy around 11.30am on Friday April 22 as teaching staff intervened and recovered a small knife from one of the pupils.
Neighbourhood Policing Inspector John Simpson said; “Any incident where a blade is taken in to school is clearly concerning to students, parents, staff and the wider community.
“This appears to have been an isolated incident, and I must stress that occurrences such as this are rare in Calderdale.
“Officers will be speaking to those involved and continuing to work closely with the school, including delivering presentations on the dangers of carrying knives and weapons over the next few weeks.”
School principal Thomas Rothwell said the incident is being dealt with.
“We take our safeguarding responsibilities very seriously,” said Mr Rothwell. “We are aware of an incident that took place at the academy and can confirm that nobody was injured with a knife or bladed implement.
“The police are currently investigating this matter and as such it would be inappropriate for us to comment any further.”
Over the last two years there have been knife incidents at other West Yorkshire schools.
James Wilson, Division Secretary of the Calderdale NUT said: “It is important that any incidents of violence in schools, are responded to promptly and appropriately in order to safeguard both students and staff.
“We understand that the school is dealing with this in line with their established policies, and that no member of staff was placed in danger.
“We have an active NUT rep and membership at Lightcliffe Academy, who have every confidence in how the head teacher and governors have dealt with this incident.
“Calderdale NUT will always support schools in taking appropriate measures to keep staff and students safe.”