Fighters opposed to the presence of foreign troops detonated one car bomb alongside a joint Iraqi and US military patrol in the Zayuna district of eastern Baghdad, as it passed near a police station on Saturday, killing two passersby, one of them a child, and wounding 10.
A second car exploded near a US military convoy in the west of the capital, police said. It was not immediately clear whether there were casualties from that blast.
The explosions came a day after a series of coordinated strikes in Baghdad and nearby areas killed more than 50 people and wounded at least 114.
US soldiers killed
Elsewhere in Iraq, six US soldiers have been killed in bomb attacks in the past two days, the US military has said.
Four soldiers were killed and two wounded by a bomb on Thursday in Tal Afar, about 390km north of Baghdad, the military said in a statement on Saturday.
The number of US troops killed
in combat in Iraq stands at 1204
A vehicle-borne bomb killed two US soldiers on Friday near Diyara, west of Baghdad, it said. The soldiers belonged to the 155th Brigade Combat Team, II Marine Expeditionary Force.
Tal Afar, west of Iraq's third-largest city, Mosul, not far from the border with Syria, has been the site of persistent violence over the past five months.
The US military thinks fighters opposed to the presence of US troops have entered Iraq from Syria and built a stronghold in the town. There is also a strong resistance presence in Mosul.
The deaths raise the number of US troops killed in combat in Iraq since the US-led invasion in March 2003 to 1204.
Forty-four US soldiers have been killed in Iraq in April, a sharp decline since January, when the toll was 107.