It was seized by police during a security alert in Newtownabbey, Co Antrim on Saturday night
Police had to evacuate a number of people from their homes during the alert.
The alarm was raised after police received a telephone call at 8.50 pm to say a device had been left in the area.
Following a search, the device was found under a railway bridge at Whitehouse Park.
Army technical officers were tasked to the scene and made the device safe.
Evacuated residents were allowed to return to their homes shortly before 1 am this morning.
TIU detectives have appealed for anyone with information to contact them on the 101 non-emergency number or through Crimestoppers on 0800 555 111.