Police arrested two of the suspects near the scene of Friday's bomb discovery in a residential area near Queen's University of Belfast. The bomb was abandoned in an alleyway.
The four men and a woman arrested are being questioned at the police's main interrogation center in Antrim west of Belfast.
IRA dissidents also forced authorities to shut down several Belfast roads Friday by placing a string of telephoned threats and hoax bombs.
The dissidents oppose Northern Ireland's 1998 peace accord and the Catholic-Protestant government it forged. Most IRA members disarmed and renounced violence in 2005.