A security alert at Cambridge House school has now ended.
A PSNI spokesman said Army Technical Officers examined a suspicious object discovered in the area “and a number of items, including a BB gun, have been removed for further examination”.
The spokesman added: “All roads have now reopened to traffic.”
Earlier the school was evacuated and children sent home.
Eye witnesses say there had been a big police presence in the area with sniffer dogs being deployed.
Mrs Elma Lutton, principal of Cambridge House Grammar school said: “Following the discovery of items on the grounds of the school, the PSNI were contacted immediately. The school was then evacuated, as a precautionary measure, on the advice of the PSNI.
“The safety of pupils at the school is of extreme importance and at no time was this compromised.”
This is the third security alert in the area over the past few weeks.