The deadliest attack yesterday took place in Saba'a al-Bour on the capital's northern outskirts, where police said three bombs killed at least 15 people.
In the Doura district of southern Baghdad, a bomb exploded in another market, killing at least eight people.
Relations between Iraq's communities have come under acute strain from the civil war in neighbouring Syria, where mainly Sunni rebels are fighting to overthrow President Bashar al Assad who is backed by Shi'ite Iran.
Nearly 6000 people have been killed in sectarian violence in Iraq so far this year, according to monitoring group Iraq Body Count, reversing a declining trend in violence after a peak in 2006-07.
In another incident yesterday, unidentified gunmen raided the house of a prominent member of a government-backed Sunni "Sahwa" militia, shooting him and his four sons dead in Latifiya, 25 miles south of Baghdad.