The US military said only one civilian was killed and eight others wounded in the explosion.
In another attack, at least five people were killed and 20 more wounded by a bomb planted near a car in the Karrada district of Baghdad, on the east side of the Tigris river.
The bomb exploded on a road leading to a checkpoint that controls access to a bridge into the Green Zone, which houses the Iraqi government and US embassy.
The US military put the casualty toll at two killed and six wounded.
Mayor's office hit
A third roadside bomb targeted a police patrol in a commercial area of eastern Baghdad's Ur district, killing three and wounding 25, according to police, although the US military said two people were killed.
North of Baghdad, a parked motorcycle loaded with explosives blew up in an open-air public market in the predominantly Shia area of Husseiniya, killing five people and wounding another 22, police and hospital officials said.
Separately, a suicide car bomber targeted the mayor's offices in Abu Ghraib, a predominantly Sunni district west of Baghdad.
|Several mainly Shia neighbourhoods of Baghdad came under attack on Monday [AFP]
The explosion occurred when the car struck a civilian vehicle before reaching the government building, damaging a nearby American vehicle that was providing security for a meeting, Major David Shoupe, a spokesman for US forces in Baghdad, said.
He said four civilians were killed and 10 people were wounded, including three US soldiers, while a local police officer said seven civilians were killed and 13 wounded.
In Diyala, northeast of Baghdad, roadside bomb struck an Iraqi army patrol killing three soldiers, near Khanaqin, close to the Iranian border, according to the province's security headquarters.
In Khalees, also in Diyala, a former al-Qaeda member who had recently been released from the US prison facility at Camp Bucca was assassinated, an official said.
Assailants also killed at least seven people in separate attacks in the northern city of Mosul, including a woman and four Iraqi security officers, according to separate police reports.
The bombings on Monday came just two days after the year's deadliest attack - a lorry bombing that killed at least 75 people near the ethnically mixed city of Kirkuk in northern Iraq.
Rescue crews continued searching on Monday for at least 12 people still missing in Saturday's explosion, which destroyed a Shia mosque and numerous mud-brick houses around it.
Starting from June 30, most of the 133,000 American troops left in Iraq will be housed in large bases outside Baghdad and other cities - unable to react unless called on for help.
The withdrawal is part of an agreement under which all US soldiers are to leave Iraq by the end of 2011.