Nearly a dozen explosions tore through predominantly Shiite Muslim areas in and around the Iraqi capital on Sunday, killing at least 39 people at crowded market places, commercial districts and car repair shops, officials said.

The attacks are part of a wave of violence that has washed across Iraq since a deadly security crackdown on a Sunni protest camp in April. Since then, the bloodshed has reached heights unseen since the country teetered on the brink of civil war in 2006 and 2007.

There was no immediate claim of responsibility for Sunday’s attacks, but insurgent groups frequently target civilians in cafes and public areas of Shiite neighborhoods in an attempt to undermine confidence in the Shiite-led government and stir up Iraq´s already simmering sectarian tensions.

The deadliest attack took place in the mostly Shiite neighborhood of Baiyaa, where a car bomb exploded inside an auto shop, killing seven people and wounding 14 others, police said.

Another car bomb in a commercial street in downtown Baghdad killed four more people, while in the eastern Ghadeer district another car bomb near a government tax office killed six people and wounded 22, authorities said.

In the Husseiniyah neighborhood, a car bombing near a restaurant killed three people and wounded 13. Another car bomb near a small market in Baghdad’s Shiite slum of Sadr City killed two, while a blast in a crowded marketplace in the primarily Shiite neighborhood of Amil killed five more and an explosion on a shopping street in the Shiiite district of al-Ameen killed another two people.

Another bomber struck the Sunni neighborhood of Radhwaniya, hitting a row of shops and killing two people and wounding eight, police said. In the Taji area just north of the capital, a car bomb near an auto repair shop killed three more people, said police.

Police said four people were killed and 11 others were wounded when a car bomb went off near a line of shops in the Shiite village of Sabaa al-Bour, about 30 kilometers (20 miles) north of Baghdad.

Also, an off-duty army officer was killed when a sticky bomb attached to his car exploded as he was driving near his house in Madain town, just south of Baghdad, police said.Saad Maan Ibrahim, an Interior Ministry spokesman said today´s attacks bear the hallmark of al-Qaida´s Iraqi branch.

"Al-Qaida terrorists have been attacking soft targets because they are not able to confront our security forces," Ibrahim said.

"They want to send a message that they are still strong. "Medical officials confirmed the casualty figures for all attacks. All officials spoke on condition of anonymity because they are not authorized to speak to the media.

At least 127 people have died in attacks in Iraq so far this month, according to an Associated Press count.