BAGHDAD -- Suicide bombers carried out twin assaults yesterday on one of Shi'ite Islam's most sacred sites and a police recruitment center, killing at least 134 people and wounding hundreds, Iraqi officials said.
Five American soldiers were also killed by a roadside bomb in the capital, the US military said.
The attacks on the Shi'ite holy city of Karbala, about 60 miles southwest of Baghdad, and Ramadi, the capital of Iraq's Sunni-dominated Anbar Province in the west, contributed to what was one of the bloodiest days since the US-led invasion of the country in 2003.
The day's attacks almost tripled the losses inflicted Wednesday when insurgents assaulted a funeral procession for the nephew of a Shi'ite Arab politician in Muqdadiyah and carried out several smaller attacks.
Before Wednesday, the country had enjoyed a measure of calm and even optimism as rival politicians talked of arranging a broad-based coalition government after elections held Dec. 15.
But insurgents made it clear over the past two days that they will continue to speak through violence.
At least 80 Sunni Arabs were killed and 61 wounded when two suicide bombers detonated explosives vests outside the recruiting center at Ramadi's glass and ceramics factory, said Majeed Tikriti, a doctor in Ramadi's hospital. In an e-mailed statement, US military authorities said only 30 people had been killed in the attack. A hospital official in Karbala said 54 people had died there.
Gunmen also ambushed and killed four Iraqi police officers in Baqubah, north of Baghdad, an Iraqi government spokesman said.
In Ramadi, more than 1,000 men had gathered at the center to apply for jobs with the Iraqi police, Marine Captain Jeffrey Pool said in an e-mailed statement. Then a suicide bomber detonated an explosives vest in the middle of the crowd, witnesses and Iraqi police said.
Wounded and panicked applicants surged forward in hopes of finding a way from the Jersey-walled entrance into the recruiting center, where another bomber was waiting to detonate an explosives belt, said one witness, Amar Oda, who was among those looking for a job.
''I just saw flesh and body parts festooning the cement barriers," Oda, 23, said from his hospital bed, where he was being treated for wounds in his head and back.
Some of those killed were tribal leaders who had come to supervise the recruitment of city residents into the country's police force, Tikriti said. Local leaders have repeatedly demanded that US and Iraqi authorities allow men from the city to serve in Iraq's armed forces. They had argued that only locally recruited soldiers could bring a measure of control to the city of 400,000 on the Euphrates River, which is considered one of the key centers of the Sunni-led insurgency.
Though US and Iraqi authorities have been reluctant to allow this, on the grounds that locally recruited soldiers are too vulnerable to coercion by insurgents, they have relented in recent weeks. Pool said in an e-mail that since recruiting began Jan. 2, officials have screened 600 applicants who met basic requirements to join the police.
While US and Iraqi military leaders consider Anbar Province the heartland of Iraq's insurgent movement, residents of Ramadi responded to the attack with fury. Nearly everyone at the scene of the attack believed that it had been ordered by Al Qaeda in Iraq, led by the Jordanian Abu Musab al-Zarqawi and considered the most violent and best-organized faction in the insurgent movement.
''Zarqawi has killed all the recruits today because he already threatened to do so," said Khalid Saadi, 42, who was at the hospital looking for his brother, Muhammed, and later learned that he was killed in one of the explosions. ''Neither the Americans nor the Shi'ites have any benefit in doing this. It is Zarqawi," he said.
Another group of people beat a doctor in the hospital after he blamed US forces for coordinating yesterday's attacks in an interview with an Iraqi journalist.
''I hope this would ring a bell," said Saad Abid Ali, a captain in the Iraqi Army who was hit by shrapnel in the legs. ''People in this city helped Zarqawi a lot, and I hope this would make them change their minds."
The scene was equally grim in Karbala, where another bomber wearing explosives detonated himself about 30 yards from the Imam Hussein shrine. Some of the victims were Shi'ite pilgrims gathered outside the Zainabiya gate to the shrine, an area flanked by markets and hotels.
A hospital assistant, Mithaa Karim Jafar, said 54 people had been killed and 143 wounded. Eight of them were Shi'ite pilgrims from Iran, Jafar said.
Footage aired on Iraqi television showed police in the city center shouting and waving pistols and assault rifles to try to control onlookers. The ground appeared to be wet and lumps of clothing and flesh lay scattered across the bloodstained street. Police and emergency workers loaded bodies onto wooden carts and pushed them away. The Al Iraqiya television network showed a pickup truck pulling away from the scene, black body bags piled in its bed.
By the time a reporter arrived on the scene, the street was once again calm. It had been cleared and guards stood watch over the shrine, which honors the martyrdom of Imam Hussein, a grandson of the Prophet Mohammed and one of the founding figures of Shi'ite Islam. The mosque, surrounded by high walls of green stone and topped by a golden dome, was still intact.
Hussein, who considered himself a legitimate successor to rule over the Islamic world after the death of Mohammed, was killed by a rival contender in a battle here in the year 680, an event many Shi'ites still mourn.
The chaos moved to the city's hospital, where doctors worked to save the lives of the wounded and make an accounting of the dead. More than 150 people jostled for a glance at a list of names of people killed in the attack. Bodies lay in a row in the hospital's garden, and more dead lay inside an overcrowded morgue.
Among the victims was a 3-year-old boy hit in the head by shrapnel. His relatives surrounded the white cloth sack in which his body lay and wailed, beating their faces.