A string of nearly a dozen apparently coordinated bombings and a shooting in cities across Iraq killed at least 32 people and wounded dozens Sunday, extending a wave of violence that is raising fears of a return to widespread killing a decade after the U.S.-led invasion.

Violence has spiked sharply in Iraq in recent months, with the death toll rising to levels not seen since 2008. Nearly 2,000 people have been killed since the beginning of April.

Most of the car bombs hit Shiite-majority areas and were the cause of most of the casualties, killing 26. The blasts hit half a dozen cities and towns in the south and center of the country. There was no claim of responsibility for any of the attacks, but they bore the hallmark of al Qaeda in Iraq, which uses car bombs, suicide bombers and coordinated attacks to target security forces, members of Iraq’s Shiite majority, and others.

The blasts began when a bomb in a parked car went off in the early morning in the industrial area of the city of Kut, killing three people and wounding 14. That was followed by acar bombing outside the city that targeted a gathering of construction workers, killing two and wounding 12, according to police.

In the oil-rich city of Basra by the Persian Gulf coast in southern Iraq, a car bomb exploded on a busy downtown street, police said. As police and rescuers rushed to the scene, a second car exploded. Six people were reported killed.

About an hour later, two parked-car bombs ripped through two neighborhoods in the southern city of Nasiriyah, 200 miles southeast of Baghdad, killing one and wounding 17, a police officer said.

And in the town of Mahmudiyah, 20 miles south of Baghdad, two civilians were killed and nine wounded when a car bomb went off in an open market.

In the Shiite holy city of Najaf, about 90 100 miles south of Baghdad, a blast struck a produce market, killing eight and wounding 28.

And in Madain, a roadside bomb and then a car bomb exploded, killing three and wounding 14. Near Hilla, a car bomb exploded in a parking lot, killing one and wounding nine.

The shooting occurred near the restive northern city of Mosul. Police officials say gunmen attacked police guarding a remote stretch of an oil pipeline, killing four and wounding five. Mosul, about 225 miles northwest of Baghdad, has been the scene of some of the deadliest unrest outside the Baghdad area in recent weeks.

In the northern city of Tuz Khormato, a roadside bomb targeted a passing police patrol, killing two officers and wounding another, a police officer said.

— Associated Press