A car bomb killed five people and wounded 23 in a crowded market on Sunday in Haswa, a small town 50km south of Baghdad, an interior ministry source said.
The area south of the Iraqi capital is populated by a mix of Sunni Arabs and Shias and is dubbed the 'Triangle of Death' because of frequent insurgent attacks.
Baghdad was under a vehicle curfew for a third day on Sunday after multiple car bombs on Thursday killed more than 200 people in a Shia stronghold of the capital, sparking revenge attacks on Sunni Arabs in the capital.
A UN envoy warned on Saturday that sectarian violence risked tearing the country apart.
Insurgent attacks and executions by death squads are killing around 100 Iraqis a day.
