The three parked car bombs exploded virtually simultaneously, tearing through a wholesale fruit and vegetable market at the height of business in the town of Jidaidat al-Shatt. The town is just outside the city of Baqouba, about 60 kilometers (35 miles) northeast of Baghdad.
Security forces sealed the roads linking Baqouba to Baghdad in an apparent effort to prevent further attacks.
Baqouba and the surrounding Diyala province was once the site of some of the fiercest fighting between U.S. forces and insurgents in Iraq, and it remains a hotbed for terrorist attacks. The area is religiously mixed, and witnessed some of the worst atrocities as Shiite militias battled Sunni insurgents for control in the years after the 2003 U.S.-led invasion.
Iraq is suffering through a spike in violence, with recent monthly death tolls rising to levels not seen since 2008. According to the United Nations, at least 1,045 Iraqi civilians and security personnel were killed in May. The tally surpassed April's 712 killed.
The surge in bloodshed, which follows months of protests by the country's Sunni Arab minority against the Shiite-led government, is raising fears that Iraq is heading for a renewed wave of widespread sectarian violence.
There was no immediate claim of responsibility for Monday's attack -- as has been the case for much of the violence in recent weeks -- but coordinated car bombings in civilian areas are frequently the work of al-Qaida's Iraq front group, known as the Islamic State of Iraq.
The three car bombs used in Monday's attack were deployed in different locations in and around the market in order to inflict most damage and casualties, the police officials said. One of the vehicles was a pickup truck loaded with produce that was parked inside the market itself.
The explosions wounded 46 people, said police officials, speaking on condition of anonymity because they were not authorized to talk to the media.
On Friday, Diyala province was the site of another deadly bombing. A suicide attacker drove an explosives-laden car into a bus carrying Iranian Shiite pilgrims visiting holy shrines in Iraq, killing 11 and wounding more than two dozen. The attack took place in the town of Muqdadiyah, about 90 kilometers (60 miles) north of Baghdad.
Provincial councilman Sadiq al-Husseini blamed that attack and Monday's bombing on al-Qaida-linked groups.
"When the grip is tightened on these groups, they resort to random attacks on residents and foreign pilgrims in order to show to the people that they are still active," he said. "Our security forces still lack intelligence and bomb detecting equipment" to stop such attacks, he added.
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