The deadliest single attack was in Hilla, where two suicide bombers triggered explosives amid a packed crowd of worshippers walking to the holy city of Karbala, police Lieutenant Karim al-Hamzawi said. Dr Mohammed Timini from Hilla Hospital's emergency room said 90 pilgrims were killed and at least 160 wounded, as queues of ambulances and private cars brought in scores of bloodied bodies.
"Among the wounded, there are 50 in a critical condition. Eighty percent of the casualties are young men, but there are women and children among the dead," he told AFP at the hospital. Tens of thousands of Shias are making their way to Karbala for the observance of Arbaeen on Friday.
Most of them are going on foot, leaving them vulnerable to attack. Elsewhere in Iraq, separate attacks killed at least 28 more Shias. In Baghdad, eight pilgrims died when their minibus was raked with bullets by unknown gunmen in Dura, while 15 more were killed and 47 wounded in three separate car bombings in other parts of the city.
Another five were gunned down in two attacks near Latifiyah, south of the capital. At least 15 more were wounded. Joint operations by US and Iraqi forces, meanwhile, netted a group of senior al Qaeda linked insurgents, Iraqi interior ministry operations director Brigadier General Abdel Karim Khalaf said.
Success against al Qaeda's militants came as security forces also put pressure on radical cleric Moqtada al Sadr's Mahdi Army militia, probing his eastern Baghdad stronghold and targeting supporters. So far, Sadr's men have stood aside during the three-week-old security operation, but Tuesday's attacks risk provoking his Shia militants into reprisals against Sunni targets.
Khalaf told AFP that 29 al Qaeda members had been rounded up since Sunday in northern Iraq, including two brothers of Abu Omar al-Baghdadi. Baghdadi heads the so-called "Islamic State of Iraq", an umbrella body for Sunni insurgent groups run by al Qaeda, and-along with al Qaeda kingpin Abu Ayyub al-Masri-is one of Iraq's most wanted men.
Nine American soldiers from the same command were killed and four more wounded in a single day in two bomb attacks on their convoys, the US military said. In one attack in Salaheddin province on Monday, six soldiers from Task Force Lightning died and three more were wounded, a statement said. Three other Task Force Lightning troops were killed in Diyala province, also north of Baghdad.
Smoke was still rising from the car-bombed ruins of Baghdad's historic book market, even as US military chiefs insisted a security sweep through the capital is putting the bombers to flight.
Despite the bombing, US commanders said Operation Fardh al-Qanoon (Imposing the Law) was having an effect, pointing to the troops conducting search operations in Sadr City, once a no-go zone controlled by Shia militias.
IRAQ MILITANTS STORM JAIL, FREE 140 Dozens of al Qaeda-led militants stormed an Iraqi jail in city of Mosul on Tuesday and freed up to 140 prisoners in one of the biggest prison breaks since the US-led invasion in 2003, police said.
As many as 300 militants led by Abu Omar al-Baghdadi, leader of the self-styled Islamic State in Iraq, attacked Mosul's Badoush prison just after sunset in the ethnically mixed city and overwhelmed police, who were forced to call the US military for backup, officials said. Most of the prisoners were believed to be insurgents, police said.