Twenty-six people were wounded in the blast in the capital city's Karrada district, according to the officials.
It happened near the site where people were getting ready to set off next week for a traditional pilgrimage to commemorate the martyrdom anniversary of Imam Moussa al-Kadhim, one of 12 revered Shiite imams, CNN reported.
It was not immediately clear who was responsible for the violence.
Shiite pilgrims have often been among the victims of bloodshed in Iraq in recent years. Thousands have been killed or wounded over the past decade.
Last May, at least 21 people died in Baghdad and dozens were wounded in three attacks targeting Shiite Muslims from around Iraq who had converged on Baghdad's Kadhimiya neighborhood.