A suicide car bomber slammed into an Iraqi army patrol in the northern city of Mosul, killing seven people and wounding 40 others, police have said.
At least 55 people were killed in bombings and shootings or were found dead on Monday, and most of the attacks were outside Baghdad.
The violence came as Iraqi and American forces prepared a new military offensive to pacify the Iraqi capital by cleansing it of militiamen and other sectarian killers that threaten to divide the country.
The biggest bombing occurred during evening rush hour in the al-Arabi neighbourhood of Mosul, some 360 kilometres northwest of Baghdad.
Two Iraqi soldiers were among the dead, and some houses and shops were damaged by the blast, said Ninevah police Brig Abdul Karim al-Jubouri.
He said the army patrol had stopped near an office of the Kurdistan Democratic Party, or KDP, which is headed by the president of Iraq's autonomous Kurdish region, Massoud Barzani.
About two hours later, a policewoman was killed in a drive-by shooting, al-Jubouri said.
Also in Mosul, two gasoline black market vendors were killed in a drive-by shooting, another police official said.
The attackers tossed a leaflet saying they would punish anyone selling fuel on the black market, the official said on condition of anonymity because of security concerns.
An off-duty policeman was also shot dead south of Mosul, said Ninevah police Brig Abdul Karim Khalaf.
Besides 25 people killed in violence on Monday, police said 30 bodies were found across the Iraqi capital, most with signs of torture.