At least 42 people were killed and dozens of others wounded in a series of evening bombings near markets in and around Baghdad on Monday.
The attacks were the latest in a wave of violence that has claimed more than 2,000 lives since the beginning of April. Militants, building on Sunni discontent with the Shia-led government, appear to be growing stronger in central and northern Iraq.
One of the deadliest attacks came at night when two bombs placed near a market blew up less than a minute apart in Baghdad's mostly Shia neighborhood of Husseiniyah, killing 10 people and wounding 30 others.
Police said the second bomb went off among a group of people who had gathered at the scene to help the victims of the first blast.
Bassem Hazim, a merchant from Husseiniyah, said he was preparing for night prayers when he heard an explosion. He went out to see what happened.
"As we came near the blast site, a second bomb went off in the crowd. We helped carry some wounded people to the hospital. All the shops closed and all the shoppers fled, he said, but "government officials are busy with trips abroad and contracts while the country is bleeding".
Earlier, police said two car bombs exploded within minutes on a commercial street in the mixed neighbourhood of Jihad in western Baghdad, killing nine people and wounding 21 others.
Four people were killed and nine others wounded when a car bomb exploded near a line of shops in the Shia-dominated area of al-Shurta al-Rabeaa.
Interior Ministry spokesman Saad Maan Ibrahim said al-Qaida was avoiding direct confrontation with the security forces and instead choosing civilian targets.
"By attacking soft targets like markets, al-Qaida wants to send a message that they are still active and still capable of striking anywhere in Iraq," he said.
Police said a car bomb exploded near a supermarket on a main commercial street in the Shia Karrada neighborhood, killing five people and wounding 16.
Another car bomb went off just after sunset near an outdoor market in the Shia suburb of Nahrawan, killing four and wounding 15.
Minutes later, a car bomb went off near a market in the Shia-majority neighborhood of New Baghdad. Police said that three people were killed and 10 others wounded. Then a second car bomb hit a bus stop in the same neighbourhood, killing two people and wounding eight others.
Two more were killed in a car explosion in the Christian-Shia district of Garage al-Amana in south-eastern Baghdad.
There were further attacks in Mosul and Tikrit, north of Baghdad.
There was no immediate claim of responsibility, but security forces and Shia residents are frequently targeted by al-Qaida's Iraq branch.