The blast in the Baghdad Jadida area in the east of the city also wounded 33 people.
Militants in Iraq frequently target crowded areas, including cafes, markets and mosques, in an effort to cause maximum casualties.
Yesterday, a suicide bomber detonated explosives at a Shiite place of worship, or husseiniyah, in Baghdad Jadida, killing 11 people.
Iraq is struggling to retake large areas overrun by a major jihadist-led militant offensive launched in June, which seized second city Mosul and swept through the country's Sunni heartland.