Police officers said that the bombs in the capital, placed in parked cars and detonated over a half-hour period, targeted commercial areas and parking lots, killing 42 people.

The deadliest blasts struck in the southeastern Nahrwan district, where two car bombs exploded simultaneously, killing seven and wounding 15, authorities said. Two other explosions hit the northern Shaab and southern Abu Dshir neighborhoods, each killing six people, officials said. Other blasts hit the neighborhoods of Mashtal, Baladiyat and Ur in eastern Baghdad, the southwestern Bayaa district and the northern Sab al-Bor and Hurriyah districts.

Meanwhile, in the northern city of Mosul, a suicide bomber drove his explosives-laden car into a group of soldiers as they were sealing off a street leading to a bank where troops were receiving salaries, killing 14, a police officer said. At least 30 people were wounded, the officer said. Also in Mosul, police said gunmen shot dead two off-duty soldiers in a drive-by shooting.

In the afternoon, a bomb blast killed four people and wounded 11 inside an outdoor market in the Sunni town of Tarmiyah, 50 kilometers (30 miles) north of Baghdad, authorities said.

No group has claim responsibility for the attacks, but systematic bombings are a favorite tactic of al-Qaida-linked groups