In Baghdad, two car bombs killed seven people and injured 26 others, China's state-run Xinhua News Agency reported.
The first car bomb exploded in a parking lot in downtown Baghdad, killing three people and wounding 12, police said. The bomb also set several nearby cars on fire.
Later, another car bomb was detonated at a busy intersection in Baghdad's northern Kadhmiyah district, killing four people and injuring 14, a police official told Xinhua.
In the central Iraqi province of Salahudin, two police officers were killed when a gunman opened fire on their vehicle, a local police official told Xinhua. The victims were driving in the city of Baiji, about 125 miles north of Baghdad.
Journalist Salah Nazal and his driver were critically injured when a sticky bomb attached to their car detonated, police told Xinhua. The explosion happened as the victims were driving through the campus of Mosul University in the city of Mosul.
Iraq has seen an increase in violence in recent years, Xinhua said. The United Nations Assistance Mission for Iraq said 8,868 Iraqis died in violent incidents in 2013.