Thirteen people were killed and 53 wounded when two near-simultaneous car bombs and a suicide attack tore through a wholesale market north of Baghdad, a police officer and a medic said.
The blasts went off in the predominantly Shiite town of Judaida al-Shat, which lies just west of Baquba, capital of Diyala province and one of the most violent areas in the country.
The attacks targeted fruit and vegetable stall owners who were crowding the market, purchasing goods for the day's trading.
Another car bomb exploded near a fish market near Taji on the northern edge of Baghdad, killing at least seven people and wounding 16 others.
No group immediately claimed responsibility for the attacks, but Al-Qaeda militants often target Iraqi civilians including Shiite Muslims in simultaneous and mass-casualty bombings.
"Al-Qaeda is behind this terrorist attack," Mohammed al-Zaidi, a vegetable vendor wounded in the Judaida al-Shat bombing told AFP, adding that the extremist group is trying to "sow religious hatred in our region ".
The unrest comes amid a surge in attacks in Iraq, with violence in May pushing the month's death toll to the highest such figure since 2008.
Over 1,000 Iraqis, the vast majority civilians, were killed in attacks in May, according to the United Nations.