The worst of the bloodshed struck the capital and surrounding areas in a spate of apparently coordinated car bombings and suicide attacks targeting the morning rush-hour.
Angry residents of one neighbourhood chased down a suspected attacker and killed him before setting his corpse ablaze.
The unrest came despite widely publicised security operations targeting militants in Baghdad and to the north and west, though the government has faced charges of not dealing with the root causes of Iraq’s worst violence since 2008.
The spike in violence since the beginning of the year, with more than 3,700 people killed in 2013, has sparked concerns Iraq is teetering on the edge of a return to the brutal all-out sectarian war of 2006-2007.
Overall, violence in Baghdad and towns just south of the capital left 57 dead on Wednesday, while four others were killed in attacks in the northern cities of Kirkuk and Mosul.
More than 190 people were wounded nationwide.
“We are poor people, and all of our things have been burned, and our home has fallen to the ground,” said Marwa, an 18-year-old resident of Shaab, a mainly Shiite district in north Baghdad where four people were killed, and cars and nearby buildings damaged by two car bombs.
“The politicians are fighting over positions and not looking after us,” she said, sobbing.
“The people are homeless because of these explosions. Who is going to compensate us? Who is going to compensate the youth?”
After the blast, local residents ran down a man suspected of planting the second car bomb, stabbed him to death, set his corpse on fire and hung it from a lamppost, according to a police officer.
Security forces later lowered it and carried it away, witnesses told AFP journalists at the scene.
Another car bomb in the Baghdad Jadidah area left three dead, also badly damaging nearby cars and shopfronts.
Further blasts went off in other major Shiite neighbourhoods including Kadhimiyah and Sadr City, while five members of a Shiite family were shot dead in their home south of the capital.
Officials, who spoke on condition of anonymity, gave varying tolls, which is common in the chaotic aftermath of bombings in the Iraqi capital.
The interior ministry, whose public casualty counts are typically markedly lower than those reported by hospital and security officials, said 20 people had died and more than 200 were wounded across Baghdad.
Iraqi lawmakers and the UN mission to Baghdad, meanwhile, condemned the violence.
No group immediately claimed responsibility for the attacks, but Sunni militants linked to Al-Qaeda frequently carry out such coordinated attacks targeting Shiites, who they regard as apostates.
Wednesday’s attacks were the latest wave of coordinated bombings to hit Baghdad this month.
On August 6, at least eight car bombs and several roadside blasts killed 31 people, while 47 people died in a spate of explosions and gun attacks in the capital on August 10.
Five days later, 24 people died in nine bombings in Baghdad.
Iraq has seen a marked rise in the level of violence this year, coinciding with demonstrations by the Sunni Arab minority against alleged ill treatment at the hands of the Shiite-led government and security forces.
More than 600 people have already been killed so far this month, according to an AFP tally.
Though diplomats and analysts have urged broad-reaching moves to tackle Sunni frustrations, which they say give militant groups room to recruit and carry out attacks, Prime Minister Nuri al-Maliki has vowed to press on with an anti-militant campaign by security forces.
Officials say security forces have in recent weeks dismantled militant training camps and bomb-making sites, arrested hundreds of alleged insurgents and killed dozens of others.
In addition to persistent security problems, though, the government has also failed to provide adequate basic services such as electricity and clean water, and corruption is widespread.
Political squabbling has likewise paralysed the government, which has passed almost no major legislation in years.