A roadside bomb went off in the residential neighbourhood of Amiriyah in Baghdad on Friday, killing one policeman and wounding another, said police.
Iraqi police were out in force on the streets of Baghdad on Friday, five days before the transfer of power to the interim Iraqi government on 30 June.
In the restive town of Baquba, three policemen were killed and one injured in an attack late on Thursday on a police station, capping a day of violence which left at least 25 people dead in the city, hospital and police sources said on Friday.
The station came under rocket-propelled grenade attack at 10:30pm (1830GMT).
Earlier in the day, 20 Iraqis and two US occupation soldiers were killed in Baquba and dozens more injured in dawn attacks on a police post and the local government headquarters and an ambush of an American patrol.
The director of the electricity department in Baquba, 60km northeast of Baghdad, lost his wife and six children as they fled the violence, said one of his employees.
Baquba was scene to some of the
Baquba witnessed some of the heaviest fighting on Thursday. US forces dropped four 500-pound bombs on a suspected hideout for resistance fighters, said a US military official.
Baquba was one of four key cities which suffered a coordinated wave of attacks on Thursday concentrating on the country's police force and killing some 100 people and injuring 320 others.
To the west of Baghdad, explosions and gunfire were heard in the flashpoint city of Falluja for a second day on Friday.
US occupation tanks and armoured vehicles maneuvered on the highway near the edges of the small city, firing in all directions, while resistance fighters in an eastern suburb
returned fire, said witnesses.
Two people were killed and seven wounded in sporadic fighting between resistance fighters and US Marines overnight, said hospital officials on Friday.
Mortar rounds were also fired, reported Aljazeera's correspondent.
Witnesses said shots were fired shortly after midnight and continued until morning. US warplanes were heard over the eastern part of the city, some 50km west of Baghdad.
US planes dropped 10 bombs on Falluja during clashes on Thursday, including 500 pound devices guided by laser, according to a military spokesman in Washington.
Most of Thursday's deaths were in the northern city of Mosul, where 62 people were killed and 216 injured in a string of car bombings of police buildings.
And in Ramadi, 110km west of Baghdad, US sources said eight people were killed when armed fighters attacked two police stations and the residence of a security official.