holy city of Karbala, killing at least 56 people and wounding 70,
according to Iraqi police and hospital officials.
The bus station bombing occurred about 200 yards from the Imam Hussein shrine in Karbala, where the grandson of Islam's Prophet Muhammad is buried — one of the most important sites for Shiites.
State television aired footage from the scene, in which rescue workers could be seen evacuating casualties. The charred body of a child laid motionless on a stretcher.
Bodies were carried to nearby ambulances as hundreds of people swarmed
around, crying out and pounding their chests in grief. Police fired into the air to disperse crowds and clear roads for emergency vehicles, but angry mobs attacked them and set two police vehicles on fire.
At least six children were among the dead, according to an official at Al-Hussein Hospital. Iranian and Pakistani pilgrims were also among the casualties, he said on condition of anonymity because he was not authorized to release the information.
Rioters surrounded the Karbala governor's office and demanded his and provincial council members' resignations — blaming them for lax security. Mobs threw stones at the governor's office and set fire to the building.
A curfew was imposed in the area, and the city's entrances were sealed off while police and soldiers patrolled the streets.
More than 70 people were also wounded in the attack, said another official at Al-Hussein Hospital on the same condition of anonymity.
"The explosion was a huge one. It took place in a crowded area," said Khalid al-Daami, head of the city's security committee. Among the dead were several women and children, he said.
Karbala lies 50 miles south of Baghdad, and is the destination of an annual Shiite pilgrimage. Hundreds of Shiite faithful were killed traveling back and forth to the city during this year's pilgrimage, which took place last month.
In Baghdad, a suicide car bomb killed 10 people on a major bridge in downtown Baghdad — the second attack on a span over the Tigris river this week, police said. The Jadriyah bridge suffered little damage. At least 15 people were wounded.
On Thursday, a suicide truck bomb collapsed the al-Sarafiyah bridge in northern Baghdad, killing 11 people and sending cars plummeting into the waters below.
Police said four would-be suicide attackers were killed Saturday in the northern city of Kirkuk when one of them detonated his explosives belt prematurely.
All four men were killed but no civilians were hurt, said police Brig. Adil Zain-Alabideen. He said all four were insurgents embarking on an attack mission, but did not elaborate.
Kirkuk lies about 180 miles north of Baghdad.
Also Saturday, gunmen attacked the western Baghdad house of Adnan al-Dulaimi, head of the largest Sunni bloc in Iraq's parliament, police said. Al-Dulaimi was not at home at the time of the attack, and is believed to be in Jordan.
Clashes erupted between his guards and the gunmen, lasting about half an hour. Five guards were wounded, police said.
Al-Dulaimi's group, the Iraqi Accordance Front, has 44 seats in parliament.
In other violence, a policeman was killed Saturday in a drive-by shooting in Hillah, about 60 miles south of Baghdad, police said.
A bomb planted in a garbage can missed a passing police patrol in Baghdad's southwestern Baya district Saturday, but injured three electricity workers who were working nearby, police said.
The U.S. military issued a statement saying American troops captured 17 suspected insurgents, including an alleged al Qaeda in Iraq member, during raids Saturday morning.
Karbala Car Bombing