The incident happened in Kenilworth Place, off the lower Newtownards Road, shortly after 8.30pm on Wednesday.
No one was in the house at the time and there are no reports of any injuries.
Army bomb experts, who attended the scene, have taken away parts of the device for further examination.
A number of properties were evacuated during the alert.
Residents have been allowed to return home.
The lower Newtownards Road, which was closed to traffic between Bridge End and Templemore Avenue, has now reopened.
Detectives in Belfast have appealed for anyone with information to come forward.