Unsuspecting motorists may have driven over a bomb left close to a sectarian interface.
A device found in east Belfast was yesterday being examined by forensic officers.
It was discovered at the junction of Albertbridge Road and Castlereagh Street in east Belfast after 6pm on Wednesday.
The area was cordoned off for 12 hours as Army officers examined the object before removing it for further investigation.
Police said they believed commuters may have driven over the device without knowing.
Naomi Long, Alliance MP for the area, said whoever was responsible could have killed members of the public if the object exploded.
She branded the incident "utterly reckless".