A roadside bomb targeting Shiite pilgrims killed 30 people in the southern city of Nasiriyah on Thursday, following bombings in Baghdad that killed at least 29. A total of 30 people were killed and 72 wounded in the attack, which occurred just west of Nasiriyah as pilgrims were walking to the holy shrine city of Karbala for Arbaeen commemorations. The attack came on the same day two Shiite neighbourhoods in Baghdad were targeted in bombings that left at least 23 people dead. For the second time in a fortnight, the Iraqi capital echoed to the wail of ambulance sirens as the fragility of the country's threadbare confessional consensus was exposed once again. Four bombs exploded in quick succession, bringing mayhem and bloodshed to two of the most densely populated districts of northern Baghdad. Two devices were detonated in Khadimiya, killing 19 and wounding 32. Another two struck the sprawling slum of Sadr City, where at least 10 people died. In a once familiar tactic, one of the bombs in Sadr city was left on a motorcycle near a queue of day labourers lining up for work.