The first bomb exploded in a wholesale clothing market in central Baghdad killing six people. The blast occurred on Sunday morning in the "Tahet al-Takya" section of the crowded Shorga market.
Two others were killed when a bomb went off in a mini-bus in al-Nahdha district in the east of the capital.
In another incident, at least 16 workers were kidnapped in Taji, 20km north of Baghdad. They were transporting goods from Baghdad to a scientific research centre.
They were travelling in more than one truck and "spirited away to an unknown location", a security official said. Ten of those kidnapped were workers at the research centre, the other six were truck drivers and labourers.
At least 80 people were kidnapped in the same region last week, about 50 have since been freed by police or released by the kidnappers.
In Baquba, a US soldier was killed in a roadside bombing. The death of the soldier from the 3rd Heavy Brigade Combat Team, 4th Infantry Division, brought to 17 the number of American personnel killed since Tuesday.