The ministry said the bombing in Karbala was one of four attacks targeting Shiite pilgrims traveling to the shrine of Imam Hussein, CNN reported.
Iraqi authorities said the pilgrims were going to the shrine to mark the end of a 40-day mourning period following Ashura, a celebration of the death of the Mohammed's grandson who died in a battle in Karbala in the year 680 A.D.
Media reports about the vehicle used in the suicide bombing were conflicting. The BBC reported it was a car, while CNN reported it was a motorcycle.
The other attacks killed three people and injured 23 others, officials said. One person died when roadside bomb exploded in western Baghdad, while two people died in a roadside blast in Hilla, Babil province. Another roadside bomb in southwestern caused only injuries, officials said.
On Monday, a suicide bomber killed 41 people and wounded 106 others also on the pilgrimage to Karbala.