Armed police were called to a school in Surrey following a "suspicious phone call" on Monday morning.
Staff and pupils at Esher C of E High School were placed into lockdown for several hours after police were called at around 11.15am.
Officers completed searches of the school, and confirmed that nothing of any concern was found, and no arrests were made.
The majority of students and staff left the premises at around 5pm, police said.
According to SurreyLive, parents and guardians were sent a text which said the "school is currently in lockdown on the advice of police outside the school.
"All pupils are safe and the site is secure."
It also asked them not to go to the school.
A statement from Surrey Police said: "We are continuing to carry out enquiries following reports of a concern for safety at Esher C of E High School earlier this morning (25 April).
"Officers were called to the school at around 11.15am following reports that the school had received a suspicious phone call. Uniformed and armed officers are continuing to carry out enquiries both inside and outside the premises to establish circumstances of the incident.
"We are working with the school as part of these enquiries. Students and staff at the school remain in the school building as a precaution at this time.
"We are hoping they will be able to leave the premises shortly.
"Contrary to speculation on social media, we have not recovered any weapons at the scene.
"No arrests have been made at this time."
Enquiries are ongoing.