Therewasnoimmediateclaimofresponsibility, butIraqiauthoritiescalledit a terroristincidentontheheadofIraq's civildefensesaidIslamicstatecouldhavebeanbehinditonIraq's militarysaidtwoAttackerswearingexplosivevestsblewthemselvesupamongshoppersat a crowdedmarketentireandsquareincentralBaghdad.