Seven car bombs struck three Shiite-majority regions of southern and central Iraq on Sunday, officials said, killing at least 13 people in the latest apparent coordinated attack by insurgents aimed at destabilizing the country.

A police officer said a parked car bomb went off early morning in the industrial area of the city of Kut, killing three people and wounding 14 others. That was followed by another car bomb outside the city targeted a gathering of construction workers that killed two and wounded 12, he added.

Kut is located 160 kilometers (100 miles) southeast of Baghdad.

In the nearby oil-rich city of Basra, twin car bombs in a busy downtown street killed five people, included a police officer, and wounded nine others, a police officer said. As police and rescuers rushed to the scene of the initial blast, the second car exploded, he added.

Basra is located some 550 kilometers (340 miles) southeast of Baghdad.

About an hour later, two parked car bombs ripped through two neighborhoods in the southern city of Nasiriyah, 320 kilometers (200 miles) southeast of Baghdad, killing one and wounding 17, another police officer said. And in the town of Mahmoudiya, 30 kilometers (20 miles) south of Baghdad, two civilians were killed and nine wounded when a car bomb went off in an open market.

Four medical officials confirmed the casualty figures. All spoke on condition of anonymity as they were not authorized to release information.

Violence has spiked sharply in Iraq in recent months, with the death toll rising to levels not seen since 2008. There was no claim of responsibility for any of the attacks, but they bore the hallmark of al-Qaida fighters in Iraq, who use car bombs, suicide bombers and coordinated attacks to target security forces, members of Iraq's Shiite majority, and others.