Dozens of people were injured.
Two car bombs exploded at a bird market in Khadumiya, just north of Baghdad, The New York Times reported.
The bombs killed 16 people and injured 45 others, including 28-year-old Waleed Salman, security and medical sources told the Times.
"I come to the bird market each Friday to sell and buy birds," said Salman, who suffered a leg injury. "I love birds as they are a sample of peace, all we want is peace but we always find blood. I lost my birds and my people today."
Two car bombs exploded in Hilla province, one in a parking lot and another at a market in the Shomali district, south of Baghdad, the Times reported. Security officials said the bombs in Hilla killed 10 people and injured 40.
The attacks marked the seventh-consecutive week of bombings on Fridays when markets are typically more crowded with people in Iraq.
Sectarian tension is worsening in the country in advance of the April elections, with some Sunnis accusing Prime Minister Nouri al-Maliki of seeking to monopolize power, the Times reported.