Al Jazeera's Mike Hanna, reporting from Baghdad, said: "It does appear the primary targets [of Wednesday's attacks] are police stations, checkpoints [and other] symbols of the attempt to create a system of law and order within Iraq".
On Haifa street, in central Baghdad, 10 people were wounded by an improvised explosive device, or IED.
In Baghdad's west, a car bomb hit a police checkpoint in Ameiriya, wounding three people, while another bombing killed two civilians and wounded eight in Adan Square in the north of the city.
Two car bombs also exploded in Ramadi, west of the capital Baghdad.
"Two terrorists" were killed attempting to rig a car with explosives in the first attack, a police source told Al Jazeera. The second car bomb explosion wounded 12 people.
In Kut, a city in Wasit province in the country's south, a suicide bomber killed at least 10 and wounded dozens others in an attack on a police station, police sources told Al Jazeera.
Lieutenant-Colonel Aziz al-Amarah, head of the rapid response police force in Wasit, said the attack killed 30 policemen and wounded 87 after destroying the police station.
"Parts of the building collapsed and there are still policemen's bodies, including the police chief, under the rubble," Amarah was quoted by Reuters news agency as saying.
A car bomber also hit a police checkpoint in al-Muqdadiya, in Diyala, killing three and wounding 18.
"The US military and the Iraqi government are adamant that forces aligned to al-Qaeda in Iraq are behind the majority attacks," our correspondent said.
"There are times, as well, when the violence is sectarian. It's very difficult to say that one organisation is behind this flurry of attacks."
Co-ordinated attacks across Iraq. Click on tabs or zoom in for more detail.
West of the Shia holy city of Karbala, a suicide car bomber targeted a police station in Al-Nasser district, killing one person and injuring at least 30, including policemen.
In the north of the country, one person died and another eight were wounded by a bomb attack in Kirkuk.
In eastern Mosul, a car bomb hit an army check point, injuring three people, including a child.
There are also early reports of an attack in a car park in Basra, southern Iraq.
Fawaz Gerges, professor of international relations at the London School of Economics, told al Jazeera: "It seems to me that the security situation is much more fragile than both the American and the Iraqi authority would like to believe.
"Unless a political solution is found, unless a national government is found that include all political persuasions, all political perspectives, the situation is likely to deteriorate in the months ahead."
Asked whether now is the right time to withdraw troops from Iraq, PJ Crowley, the state department's spokesman, said the phased withdrawal was in "accordance with the agreement" signed by the Iraqi government.
"We're withdrawing our combat troops in accordance with the status of forces agreement that we've reached with the sovereign government of Iraq," he told Al Jazeera.
"We are not surprised by this spike of violence; we anticipated it ... al-Qaeda is trying to drive a wedge between the government and the people.
"But these attacks are directed at a sovereign government elected by the people of Iraq and we believe that the Iraqi security forces [and] the Iraqi government are fully prepared to deal with this upsurge in violence."
Since the Iraqi parliamentary elections in March 2010, no two Iraqi blocs have yet managed to form a governing coalition with the necessary majority.
On Tuesday, a suicide car bomber targeted a police checkpoint in eastern Baquba, the capital of Diyala province.
The attack killed three people and wounded 13 others, mainly police.
It coincided with the arrival of the convoy for Diyala's governor. A bodyguard for the governor was among the dead.
"Certainly, [there has been] a flurry of violent activity in recent hours, coming to that deadline by the United States for its self-declared draw-down of its troops in Iraq," our correspondent said.
"Iraq authorities have arrested a large number of people who they say are aligned to al-Qaeda."