Also, a police general and the government's industry minister escaped assassination in attacks on their vehicles.
The car bomb on Sunday exploded near an Iraqi police patrol near the northern city of Kirkuk, killing three officers and injuring one civilian, army Major General Anwar Muhammad Amin said.
In Baghdad, men fired on a car carrying police Brigadier General Abdul Hussein Hamid Khalaf on Sunday, wounding him and killing his son, police said.
Late on Saturday, Industry Minister Osama Abdul Aziz Najafi escaped assassination when men fired on his convoy in western Baghdad, a ministry official said on condition of anonymity. Four bodyguards were wounded, the official said. Also in Baghdad, Shia cleric Adil al-Janabi and one of his bodyguards were killed in a drive-by shooting on Saturday night, police said.
The CH-47 Chinook caught fire
on the ground
In Ramadi, fire destroyed a US military helicopter, injuring one crewman, the US military said on Sunday. The CH-47 Chinook, valued at $13.5 million (11.3 million euro), caught fire on the ground on Saturday night, the US military said.
No further details were released pending an investigation.
The attacks occurred a day after bombers struck in Baghdad and a Shia city south of the capital, killing 26 people and injuring nearly 50.
A web statement in the name of al-Qaida in Iraq took responsibility for the Baghdad bombing, although it was impossible to confirm the authenticity. There was no immediate claim for the Hillah attacks.
Groups announce spokesman
Meanwhile, two other armed groups said on Sunday that they have named a new spokesman to silence those who claim to speak for the resistance.
In a joint statement posted on an Islamic website, the Islamic Army in Iraq and the Army of Mujahidin said they had chosen Ibrahim Youssef al-Shammari as their spokesman.
Two Iraqi groups announced a
joint spokesman on Sunday
The little-known al-Shammari appeared on Aljazeera on Sunday "to silence all those who talk in the name of the mujahidin".
A-Shammari said the resistance "has a realistic and truthful political project," adding that talks with other armed factions to come up with a unified position was taking place. He did not elaborate further.
The announcement comes on the heel of a web statement issued in the name of The Islamic Army in Iraq, the Army of Mujahidin and the Ansar al-Sunnah Army which threatened the life of a Sunni Arab politician.
Ayham al-Samarie had announced the formation of a political group he claimed represented the demands of an umbrella organisation of fighters.
The three groups accused the dual US-Iraqi national of spreading lies.