The latest violence, just months ahead of landmark elections, pushed the number of slain so far this year above 6,000 as the country endures its worst prolonged spate of bloodshed since 2008.
Although there have been no claims of responsibility for much of the unrest, authorities are concerned about a resurgent Al-Qaeda, emboldened by the civil war raging in neighbouring Syria.
Most of the violence struck Baghdad and Sunni Arab areas of northern and western Iraq, which have borne the brunt of the months-long spike in bloodletting.
Four suicide bombers detonated their explosives, but the carnage could have been much worse because security forces shot dead several would-be suicide attackers.
Meanwhile, in two separate areas of the capital, police found the bodies of 14 men, all in their 20s or 30s, and all shot dead, medical officials said.
Eight of the corpses were found blindfolded in the mostly Sunni Dura neighbourhood, while six others had been dumped in a canal in mostly Shiite Shuala.
In the northern district of Hurriyah, a family of five — three men and two women — were shot dead in their home in a pre-dawn attack.
At the peak of sectarian fighting, Sunni and Shiite militiamen would regularly carry out tit-for-tat kidnappings and assassinations and leave scores of corpses littering the streets, many of them bound, blindfolded and showing signs of torture.
Shootings, bombings and mortar fire in various other parts of the capital left five others dead Wednesday.
Elsewhere, shootings and bombings — including four suicide attacks — killed 25 people.
In Abu Ghraib, west of Baghdad, a man blew himself up in the middle of a funeral, killing nine people.
In northern Diyala province, a vehicle rigged with explosives and detonated by a suicide attacker killed three members of Kurdish peshmerga forces.
Two separate attacks involving multiple suicide bombers against police near Ramadi, west of Baghdad, killed at least seven policemen and left 15 others wounded.
One of the attacks involved a car bomb set off by a suicide attacker on the western outskirts of the city, followed by a firefight between militants and police in which four suicide bombers blew themselves up.
Five policemen were killed and 11 were wounded.
A separate suicide bombing at a police station just north of the city killed two more policemen and left four wounded.
Ramadi is the capital of the western desert province of Anbar, which shares a long border with Syria. Sunni militants linked to Al-Qaeda have exploited the relative lack of security to set up training camps and carry out attacks on both sides of the frontier.
Shootings in and around Mosul left five people dead, and a Sunni anti-Qaeda militiaman was gunned down in Salaheddin province.
The government has trumpeted wide-ranging security operations targeting militants, primarily in Sunni-majority areas in the north and west, including the arrest of 25 people on Wednesday, but daily attacks have shown no sign of abating.
More than 6,000 people have been killed so far this year, according to an AFP tally based on reports from security and medical officials.
Diplomats, analysts and rights groups say the government is not doing enough to address the root causes of the unrest, particularly disquiet among Sunnis over alleged mistreatment at the hands of the Shiite-led authorities.
Prime Minister Nuri al-Maliki used a recent trip to Washington to push for greater intelligence sharing and the timely delivery of new weapons systems in a bid to combat militants, while France and Turkey have offered assistance.