The attacks on Tuesday made for a violent backdrop as Iraqi political leaders prepared to resume talks to finalise the constitution by 15 August.
On Tuesday, a driver detonated his vehicle near a US convoy in downtown Baghdad, killing at least five Iraqi civilians and injuring 11 others, police said. There was no report on American casualties.
The attack occurred in the early afternoon near al-Tahrir Square in the heart of the city, police Captain Abdul-Hussein Munasaf said. Five civilian cars, one US army Humvee and an SUV were damaged. The US and Iraqi authorities sealed off the area.
Earlier, four police officers were killed and one wounded when their patrol car was attacked in the east of the capital on Tuesday, an Interior Ministry official said.
The officers had been asleep in their vehicle when two carloads of assailants fired on them around 8am in the eastern New Baghdad neighbourhood of the capital, said Lieutenant-Colonel Ahmad Abud.
Four police officers were killed
while asleep in their vehicle
The men had spent the night on patrol and fell asleep as they were waiting to be replaced by another patrol, he said.
Their weapons were in the back seat of their vehicle, he added.
Two others were shot dead on al-Ghadir Street, also in east Baghdad, and one police officer was killed and three were wounded in the capital's western district of al-Adil.
Also on Tuesday, police Captain Haidar Mizhir Salih and another police officer were shot and killed as they were heading to work around 8am in Baghdad's southern district of Dura, said 1st Lieutenant Muhammad Hannun.
Another police officer was shot dead in the south of the capital.
And one police officer was killed and another wounded in Baquba, 60km north of the capital, police Lieutenant Khalid Ahmad said.