Smoke rises from the wreckage of a truck used in the first of two suicide car bombings in Kirkuk, 290 kilometers (180 miles) north of Baghdad, Iraq, Monday, July 16, 2007. Twin suicide car bombings exploded within 20 minutes of each other in the northern city of Kirkuk on Monday, killing at least 80 people and wounding around 150 in attacks targeting a Kurdish political office and ripping through an outdoor market, police said. [AP]

The blasts in this city of deep tensions between Kurds and Arabs came as Sunni insurgents were believed to be moving north, fleeing a U.S. offensive around Baghdad and consolidating to carry out deadly bombings.

The massive explosion from the truck bomb around noon blasted a 30-foot-deep crater and damaged part of the roof of the headquarters of the Patriotic Union of Kurdistan, the party of President Jalal Talabani.

The main street outside the office was strewn with blackened husks of two dozen cars, and at least 10 shops were damaged, as well as part of the fence of the nearby Kirkuk Castle, a historic fortress that is one of the city's most prominent landmarks. The blast killed at least 80 people and wounded more than 183, according to police Brig. Burhan Tayeb Taha.

Twenty minutes later, a car bomb exploded about 700 yards away in the Haseer market, an outdoor souk frequented by Kurds, Maj. Gen. Jamal Tahir, the police chief, told The Associated Press. The market was largely empty after the first attack, and the explosion caused several injuries.

Hours later, a car bomb exploded in the Domiz region of southern Kirkuk, killing a police officer and wounding six other policemen, Tahir said.

Oil-rich Kirkuk, 180 miles north of Baghdad, is a center of tensions between Arabs and Kurds, who want to include the area in the autonomous Kurdish region of the north. Violence in the city, though frequent, tends to be on a smaller scale of shootings, roadside bombs and kidnap-slayings. Monday's blasts came just over a week after one of the Iraq conflict's deadliest suicide attacks hit a village about 50 miles south of Kirkuk, killing more than 160 people.

Iraqi officials have said Sunni insurgents are moving farther north to carry out attacks, fleeing U.S. offensives in and around Baghdad, including in the city of Baqouba, a stronghold of extremists on the capital's northwestern doorstep. The month-old sweeps, fueled by 28,000 new U.S. troops sent to Iraq this year, aim to pacify the capital and boost the government of Prime Minister Nouri al-Maliki.

U.S. troops launched a new offensive south of Baghdad on Monday, aimed at stopping weapons and fighters from moving into the capital, the military said.

It did not say where the new sweep, codenamed Marne Avalanche, was taking place. In recent days, U.S. commanders have said they plan new operations to cut off an insurgent supply route southwest of the city, running from western Anbar province. An offensive has been ongoing for the past month in a region southeast of Baghdad.

Violence appears to have eased in Baghdad in recent weeks ¡ª but attacks, including deadly car bombs, happen daily.

A string of attacks Monday in the capital killed at least 19 people.

In the deadliest, a roadside bomb exploded near a passing Iraqi army patrol on the northeastern outskirts, killing five soldiers and wounding nine, an army officer said.

A suicide car bombing in Baghdad struck a police checkpoint on a major road leading to a major Interior Ministry building inside the Green Zone. Five policemen were killed and 25 people wounded, a police official said.

Another car bomb exploded in the central district of Karradah, killing one person, wounding three and setting nearby shops ablaze, a police official said.

A third car bomb exploded in the garage of a man's home in eastern Baghdad, killing his two daughters. The man told police he had been kidnapped in the south of the capital Sunday night, but was released. When he returned home, the car exploded, a police official said. Investigators found a timer in the wreckage, the official said.

Other deaths in Baghdad were caused by mortars, shootings and roadside bombs, according to police. On Sunday, 22 bullet-riddled bodies were found dumped in various locations of Baghdad, the latest victims of apparent sectarian violence, police said. All the officials spoke on condition of anonymity because they were not authorized to release the reports.

The military said an American soldier died from wounds received Sunday by a bombing in Ninevah province, northwest of Kirkuk. Another soldier died Sunday of a non-battle related cause in the southern city of Diwaniyah, the U.S. military said Monday.

Prime Minister Nouri al-Maliki said he hoped Iraqi forces would have enough training by the end of the year to take over security duties from the Americans ¡ª backing off comments Saturday insisting the Iraqi army and police were ready to do so at any time.

"I hope this here will be the end of the building of our forces so that we are prepared to take control of security. This needs the cooperation of everyone involved, both us and the coalition forces," he told NBC's "Today" show.

"As soon as we reach this level of readiness, the door will be open for dialogue between us and Americans about our future plans. Now we are thinking as politicians about how to maintain robust long-term relations with the Americans whether they remain on Iraqi soil or pull out from Iraq," he said.

On Saturday, al-Maliki said Iraqi forces were ready to take over from the Americans "whenever they want" to withdraw ¡ª an apparent show of frustration with the turbulent debate in Washington over a pullout and criticism of his government.

Former U.S. Rep. Lee Hamilton, co-chairman of the Iraq Study Group, told NBC on Monday he's "extremely doubtful" that al-Maliki will be able to secure the country and allow American forces to leave any time soon.

"All of the support efforts, logistical and medical and so forth, they are not close to being able to meet," Hamilton said.

Marine Gen. Peter Pace, the U.S. military's top general, said Monday that the Joint Chiefs of Staff is weighing a range of possible new directions in Iraq, including, if President Bush deems it necessary, an even bigger troop buildup.

The Iraqi parliament convened Monday as politicians tried to end boycotts of the legislature that are holding up work on crucial reforms sought by Washington. The slowness of the reforms has fueled U.S. calls for the withdrawal of American forces.