The three who died were killed in an attack on a police convoy in central Baghdad, CNN reported. At least 15 others were injured.
Another 20 other people were wounded when insurgents targeted separate convoys of a senior Interior Ministry official near Beirut Square, a district mayor in the Shaab neighborhood and police commandos near Sadr City, officials said.
In northern Iraq, U.S. and Iraqi forces killed four suspected terrorists and destroyed an al-Qaida in Iraq hiding place Thursday during a raid, CNN reported.
During the operation near Baquba in Iraq's Diyala province, U.S. military officials said troops destroyed a facility where weapons were stored.
Coalition forces also discovered a "tunnel system, fighting positions, weapons, military-style assault vests and documents detailing terrorist operations," a military spokesman said.
The raid was targeting a suicide bombing network.