The morning blast in the eastern neighbourhood of Baghdad Jadida also wounded more than 30 people, the officials said.
There was no immediate claim of responsibility for the attack, but suicide bombings are a tactic almost exclusively employed by Sunni extremists in Iraq, including the Islamic State (IS) jihadist group.
IS spearheaded a sweeping offensive last June that overran large areas north and west of Baghdad, and Iraqi forces are now battling to push the jihadists back.
Saturday’s attack illustrates the persistent danger of violence in the Iraqi capital even as the nightly curfew was set to end at midnight (2100 GMT) in Baghdad.
Lifting the curfew is a major change to a longstanding policy aimed at curbing violence in the capital by limiting movement at night, which has failed to stop frequent bombings.
Iraqi Prime Minister Haider al-Abadi ordered the move earlier in the week, a decision his spokesman said was taken so there would “be normal life as much as possible, despite the existence of a state of war”. (AFP)