Published Friday, 04 April 2014
Police are currently at the scene. (© UTV)
The weapon was discovered in a bag in the Norfolk Parade area of the city on Friday morning.
It has been taken away by police.
A number homes were evacuated during the security operation.
The families have now been allowed to return to the area.
Sinn Féin councillor Caoimhin Mac Giolla Mhin said a child could have lifted the gun.
"At that time of the morning there are all sorts of people going to school with their kids and anybody could have lifted this from what I could see," he explained.
"It's quite a dangerous situation to leave a weapon in a highly built up area."
© UTV News