Armed youths were detained by police following an incident involving an air rifle outside Greenfield School on Wednesday morning.
Police confirmed the school was on “lockdown” for a couple of hours from just after 9am through to about midday.
The school was alerted to reports that three youths armed with an air rifle were loitering just outside the school grounds.
Pupils were kept indoors all morning as a precautionary measure.
Neighbourhood Police Team Sergeant Mark Edwards told Aycliffe Today: “I can confirm that there was an incident just after 9am where a couple of youths were seen in possession of an air weapon and there were natural concerns which resulted in the school being put on lock down for a couple of hours.
“The Neighbourhood Police Team took on the investigation and two male youths were apprehended and interviewed by officers.
“An air weapon was recovered and seized from one of them so we are satisfied that we’re dealing with all who were involved.”
The school’s head teacher reportedly said: “We judged it posed a minor threat so we have kept the pupils inside until the police assured us they dealt with the incident and until there was no threat of danger to the children.
“Everything has been very calm and orderly and everybody managed the situation very well.”