Army bomb experts found a small viable bomb during a security alert in the Jamaica Street area of north Belfast yesterday.
Jamaica Street was closed to traffic and motorists were advised to follow diversions.
A number of residents were also evacuated from their homes.
Police said an unmanned aerial drone was used to help monitor the situation.
The alert was declared over by the PSNI just after 8pm.
Police are asking anyone with information to contact detectives on 0845 600 8000 or to provide information anonymously to Crimestoppers on 0800 555 111.