It follows the lifting of a curfew imposed ahead of the sentencing of Saddam Hussein.
Two mortar rounds fell on the east Baghdad suburb of Sadr City, killing eight people and injuring 15.
Earlier, a mortar attack near the health ministry killed three people and injured five.
About the same time, a car bomb exploded near the Nida mosque in the northern Sunni stronghold of Adhamiyah, killing one person.
Another mortar attack in downtown Jumhuriyah Street killed another person and wounded eight.
Not long after that, a pair of mortars crashed on Kadhimiyah neighborhood, killing two people and wounding eight.
In the capital's southwest Al-Amil neighbourhood, three civilians were killed and another three wounded in a car bomb attack, while a member of the National Police was killed in a suicide car bombing against a southern checkpoint.
South of the city, a car bomb exploded in Mahmudiyah, killing six people and injuring another 26.
In nearby Iskandriyah, another bomb exploded in a residential area killing a man and his 13-year-old son.
Further violence in Diyala
In the eastern region of Diyala, which was also under curfew along with Baghdad and Salaheddin provinces, at least 17 people were killed, including four in a single car bomb attack.
The booby-trapped car exploded in a market in Muqdadiyah town, north of the provincial capital, Baquba.
In a series of shootings across the province carried out by unknown gunmen, eight people were killed, including four in Baquba.
Five Iraqis were killed when clashes broke out in the village of Dhida near Muqdadiyah.
Two police lieutenants were killed in Saddam Hussein's hometown, Tikrit, while hundreds of his supporters demonstrated in Salaheddin against the death sentence.
