BAGHDAD -- Nearly simultaneous suicide bombings at three military checkpoints in northern Iraq killed at least 18 people yesterday, police said, and dozens were hurt in Baghdad by a car bomb apparently aimed at a police convoy.
US and Iraqi troops, meanwhile, launched an offensive against insurgents in the volatile northern town of Tal Afar.
The triple bombings outside the town of Hawija, about 130 miles north of Baghdad, occurred within a few minutes of one another at checkpoints manned by Iraqi soldiers, said Iraqi police General Ahmed Obeidi.
At 9:30 a.m., a suicide bomber tried to drive his car onto a US military base in Baggara, 3 miles west of Hawija, but couldn't get past an Iraqi Army checkpoint, Obeidi said. The bomber detonated his car at the checkpoint and killed an Iraqi soldier.
Minutes later, another suicide car bomber struck a checkpoint in Aziziya, on the north side of Hawija, killing two Iraqi soldiers.
The deadliest bombing occurred soon afterward in Dibis, a town 2 miles west of Hawija. Iraqi soldiers grew suspicious of a car in a line of vehicles at the Dibis checkpoint, Obeidi said. When the soldiers approached the car, he said, it exploded, killing 11 Iraqis, including five soldiers, and setting more than 10 cars ablaze.
Jasim Hamad, a hospital physician, said three young children were among the dead.
The US military, meanwhile, reported that five US soldiers had been killed in two days: Two Marines died in separate attacks Monday outside Fallujah; two 42d Infantry Division soldiers died in an attack on their base in Tikrit yesterday; and another soldier died when a roadside bomb exploded yesterday near his vehicle north of Baghdad.
Also, a Sunni Muslim cleric who had been abducted Sunday, Salam Kardici, was found shot to death yesterday in the southern port of Basra, where a Shi'ite Muslim cleric was assassinated last week.
Attacks on Iraqi and foreign security forces have accounted for a large proportion of the more than 850 killings in Iraq since a transitional government led by Prime Minister Ibrahim al-Jaafari took office in late April.
The car bomb in Baghdad early yesterday wounded 28 people, including a policeman, according to a hospital official who spoke on the condition of anonymity.
Witnesses in the neighborhood of Shula, in northern Baghdad, said the bomb apparently was intended for a convoy of police officers who passed the same spot every morning on their way to set up a security checkpoint nearby.
''We knew it would happen here one day," said Esmail Thamir, 42, who owns a real estate office 15 yards from where the car containing the bomb was parked. ''They shouldn't set up their checkpoints in these places. . . . They shouldn't expose civilians to their danger."
Details about the joint US-Iraqi military assault in Tal Afar were not immediately available last night, but a US military spokesman in Baghdad confirmed that an operation was underway there.
Over the weekend, local officials and religious and tribal leaders from Tal Afar held talks with Iraqi and US military representatives that yielded a four-point agreement aimed at curbing insurgent and sectarian violence. The accord acknowledged, however, that failure to achieve peace would make a large-scale military incursion unavoidable.
In Baghdad, a government spokesman backed away from recent statements that ousted president Saddam Hussein would face trial within two months on charges focusing on 12 crimes during his tenure.
Laith Kubba, spokesman for the prime minister, said any information about the prosecution would come from the special tribunal formed to try Hussein. Last week, President Jalal Talabani had said Hussein would be tried within two months.
Yesterday, however, Kubba said the tribunal ''assured me that they have a press officer and that they would like the information to be taken from them." A tribunal spokesman could not be reached by telephone.
Also yesterday, a Sunni Arab politician said two insurgent groups were willing to negotiate with the government. Former electricity minister Ayham al-Samarie told The Associated Press the Islamic Army in Iraq and the Army of Mujahideen were ready to open talks with the Shi'ite-led government -- talks aimed at eventually joining the political process.