An old army bottle found at Thiepval Barracks caused a security alert in Lisburn last Friday evening.
Homes had to be evacuated and the Belsize Road was closed during the operation, which lasted until almost 9pm.
Army bomb experts were tasked to examine a suspicious item within the complex.
On Monday there was a security alert at a primary school in Dunmurry which was also declared a hoax.
Pupils were moved from Christ the Redeemer Primary School at 9am after police were contacted about a suspicious object outside the school fence.
A section of Lagmore Drive was closed while army bomb experts investigated. The pupils were taken to a nearby church hall.
The alert disrupted the funeral of Patrick McDonnell, the Belfast man killed in a car accident in America last month.
Assembly member Jennifer McCann said: “This is absolutely disgraceful, whoever was behind this. It has caused major disruption for the children, teachers and also parents.”
Northern Ireland has been on high alert since a bomb blast injured a prison officer a fortnight ago.
The bomb detonated under the 52-year-old officer’s van as he was driving to work.
It is thought the bomb may have dislodged from the vehicle as it was going over a speed bump.
Dissident republican terror group, the New IRA, claimed responsibility for the attack.
The group said the man was targeted for training officers at Maghaberry Prison.
After Friday’s attack, the Police Service of Northern Ireland said it was deeply concerned that dissident republicans were determined to escalate their activities to mark the centenary of the 1916 Easter Rising.