A wave of car bombs and shootings across Iraq killed at least 36 people on Sunday, police sources said.
No group immediately claimed responsibility for the attacks, which appeared coordinated, but Sunni Islamist insurgents, including an al Qaeda affiliate, have been regaining momentum in recent months.
The civil war in neighbouring Syria has aggravated sectarian divisions in Iraq, fraying an uneasy government coalition of Shi'ite, Sunni and ethnic Kurdish factions.
The deadliest attacks were in the city of Hilla, where two parked car bombs exploded simultaneously near a busy market and a third blew up near vehicle repair workshops, killing nine people in total, police said.
"I was about to get my breakfast in a nearby restaurant when a huge explosion happened and smoke and dust filled the place. Before I had taken a step forward another explosion happened," said Abu Ahmed, who runs a grocery store.
"I ran to check on my son who was covering for me in my shop and found him covered with blood among many other bodies. There is no trace left of my shop."
In Baghdad's Shi'ite eastern district, a parked car bomb exploded in a commercial street killing at least five people and wounding 17, police said.
Another explosion took place in the oil-exporting southern city of Basra, where a car bomb blew up near another vehicle repair workshop killing five people. A car bomb in the city of Kerbala killed two others, police said.
In the capital, three security personnel were killed when a car bomb exploded near the convoy of the head of Baghdad provincial council, and two more people were killed when a roadside bomb blew up in a western outskirt.
A further two car bombs exploded inside a market killing two people and wounding another 16 in the town of Dibis, 250 km (155 miles) north of Baghdad, police said.
In a separate incident, gunmen riding a car shot dead two Shi'ite farmers who had recently returned to their homes in a town east of Baquba, 65 km (40 miles) northeast of Baghdad. In the same area, militants engaged in clashes with policemen at a checkpoint, killing two of them.
On the southern outskirts of Baghdad, police said they found the bodies of four Sunnis who were kidnapped from their homes last night by unidentified gunmen. The corpses had gunshot wounds and were handcuffed.
About 800 Iraqis were killed in August, according to the United Nations, with more than a third of the deadly attacks happening in Baghdad.
The bloodshed, 18 months after U.S. troops withdrew from Iraq, has stirred concerns about a return to the sectarian slaughter of 2006-7, when the monthly death toll sometimes topped 3,000.