Pupils were evacuated at a school in Warwick after an email threat sparked concern as police rushed to the scene.
Parents were urged to stay away from Myton School after Year 11 students were forced to leave in the middle of an exam.
The ambulance service was called to the scene at 11.44am today.
Warwickshire Police said all students were out of the building while emergency services responded.
Pupils were evacuated at a school in Warwick after an email threat sparked concern as police rushed to the sceneParamedics were later stood down and no patients required treatment.
Myton School wrote on social media: "Parents and carers, this morning we received a vague threat via email against our school.
"As always the first priority was the safety of students and staff, who were all evacuated from the buildings.
"We appreciate the communication was difficult at this time as we had such limited access to systems.
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"Thank you very much for your prompt responses which allowed us to send Year 7 to 10 students home."
A police presence remains around the school with a cordon in place.
Students at the school were sent home while police investigations continue.
Local policing commander for south Warwickshire, Chief Inspector Faz Chishty said officers will remain in the area for "some time".
Parents were urged to stay away from Myton School after Year 11 students were forced to leave in the middle of an examGoogle mapsThe school added: "Throughout this incident the children have been amazing and Mr Perry would like to thank every single one of them for acting so responsibly in a very trying situation.
"The Police Chief inspector has said thank you for your patience and support.
"He also thanks staff and students for their very prompt responses."
It is currently unknown whether the school will re-open tomorrow.
