A series of attacks — including two homicide car bombings — in the northern city of Kirkuk Sunday killed 24 people and wounded dozens, police said.

In political developments, Iraq's second-largest Sunni Arab party rejected a proposed bill that would pave the way for Iraq to become a federated nation, saying it would divide the country.

"This country which has been united in its entire history cannot be divided into regions. It is a step toward dividing Iraqi into mini-states," Mishan al-Saadi, a senior member of the National Dialogue Front, told the Associated Press.

Some Shiites want to create an autonomous region in the oil rich south where they are dominant. That would leave Sunni Arabs with Iraq's western provinces — which are mostly desert.

The idea of federalism is enshrined in the Iraqi constitution, but before it can be implemented in practice the mechanics have to be legislated and approved in a referendum.

The northern Kurdish area is the only existing federal region in Iraq. The Kurdish region is much more economically stable and peaceful than other parts of Iraq.

Just outside the region, a homicide truck bomb exploded in the morning in the center of Kirkuk, 180 miles north of Baghdad, killing 18 and wounding 55, police Brig. Sarhat Qadir said. A few hours later, a homicide car bomb rammed into a joint U.S.-Iraqi army patrol in the south of the city, killing at least three bystanders and wounding eight others, he said.

Two roadside bombs later targeted police patrols in separate parts of the city. One killed two civilians and wounded four, while the second wounded three civilians, Qadir said.

Shortly afterward, a parked car bomb exploded near the house of Sunni sheik Waasif al-Obeidi, killing one of his bodyguards and wounding two guards and six bystanders, Qadir said. Al-Obeidi was not in his house at the time.

In the afternoon, a parked car bomb exploded as a joint Iraqi police and army patrol passed by in southern Kirkuk, wounding two policemen and four soldiers, police Col. Burhan Tayib said.

In the truck suicide bombing, a gunman in the truck opened fire on civilians before the vehicle exploded near the city's criminal court and the headquarters of two main Kurdish political parties, the Kurdistan Democratic Party and the Patriotic Union of Kurdistan, Qadir said.

The Patriotic Union of Kurdistan is run by Iraq's President Jalal Talabani, while the president of Kurdistan, Massoud Barzani, runs the Kurdistan Democratic Party.

Barzani recently angered many in Baghdad when he ordered the Iraqi national flag to be replaced with the Kurdish banner on all government buildings in the autonomous Kurdish region in the north.

His decision, which was announced Sept. 1, led to an outcry, particularly among Sunni Arab lawmakers who fear that Kurds are pushing for secession under the nation's new federal system.

Kirkuk, the center of Iraq's vast northern oil fields, is the subject of rival claims by the area's Arabs, Kurds and Turkomen.

A series of near simultaneous mortar and bomb attacks targeting police patrols in Fallujah, 40 miles west of Baghdad, also killed four people, including two policemen, and wounded 10, police Lt. Mohammed Ismail said. U.S. military authorities used loudspeakers to announce a vehicle ban in the city.

A roadside bomb detonated in the center of Fallujah, followed a few minutes later by a car bomb attack and a blast from an explosives-rigged motorcycle in separate areas of the city, Ismail said, without providing a breakdown of casualties.

Shortly afterward, a mortar round hit the area of a U.S. and Iraqi police base in the center of the city, and clashes erupted between gunmen and police nearby. Another mortar fell in an Iraqi army base in western Fallujah but did not cause any casualties, Ismail said.

In the capital, a bomb left in plastic bag exploded on the central commercial Jumhouriyah street, killing two civilians and wounding eight, police 1st Lt. Ahmed Mohammed Ali said.

In Baghdad, the bloodshed has escalated sharply in the past week, with more than 180 people killed since Wednesday — either slain by bombs and gunfire or tortured and shot before being dumped on city streets or in rivers, a hallmark of reprisal killings being waged between Shiite and Sunni Muslims.

On Sunday, the bullet-riddled bodies of four unidentified men were found in separate neighborhoods in east Baghdad. All were blindfolded and had their hands and legs tied, police Maj. Mahir Hamad Mussa said.

Another two bodies were found in the Tigris river in central Baghdad. Both had been shot, and one had been decapitated, said police 1st Lt. Ahmed Mohammed Ali.

In the city of Kut, 100 miles southeast of Baghdad, a blindfolded and bound body was taken to the morgue after being found dumped in a river, morgue official Maamoun Ajeel said.

To the south, in Iraq's second-largest city of Basra, Ali al-Safi, a representative of Grand Ayatollah Ali al-Sistani in the city, survived a roadside bomb attack that targeted his convoy as it passed by a mosque. One of his guards was wounded wounding one of his guards and one car was damaged, said police Col. Karim al-Zaidi.