In the latest attack, a car bomb ripped through a fruit and vegetable market crowded with Friday morning shoppers.
Destroyed stalls lay in pools of blood in the al-Sharia market in the southern city of Hillah, in Iraq's Shia heartland. The scenes mirrored the devastation in Balad, the Shia town in the middle of a Sunni region north of Baghdad hit by a triple suicide bombing Thursday, a far more lethal attack.
Unidentified bodies in bags or under pieces of cardboard lay on the ground in a Balad hospital courtyard Friday. Weeping women went from body to body searching for loved ones. The blasts reduced nearly an entire block in the market district to a giant mound of twisted metal and bricks strewn with bananas, tomatoes and other produce.
"Why does such a thing happen to us? We ask the government and Arab countries to help us," cried Mohammed Mahdi Jassim, a Balad resident.
Both attacks seemed staged to kill or maim as many civilians as possible, tearing through busy markets and commercial streets. At least 10 people were killed in Hillah and 102 in Balad. At least 22 of those killed both days were women and children.
Insurgents have vowed to derail the October 15 referendum, opposed by Iraq's Sunni Arab minority, and the recent surge of violence has killed at least 200 people -- including 13 US service members -- in the past five days.
The Sunni-led al-Qaida in Iraq, the most feared insurgent group, has declared "all-out war" on Shias, and since a Shia-majority government took power April 28, suicide bombers have killed at least 1,345 people, according to an Associated Press count.
Intimidating Shias from voting in the referendum could boost Sunni attempts to reject the charter, and the tactic was having an effect among some in Balad and surrounding Shia towns.
Mohammed Kadhim, 25, a Shia shopkeeper in the town of Dujail, said he would not allow his family to vote. "I'm responsible for their safety after what happened in Balad, and what is happening in the whole country with the occupation forces and the government."
Hussein Ali, a 67-year-old Shia in Balad, also said he would stay away from the polls. "I will not take part in this game that kills Iraqis," he said.
The sharpening Sunni-Shia divide is a blow to hopes that the constitution would unite Iraqis and bring stability, allowing the US military to begin pulling out troops. Withdrawals projected for next spring may have to be pushed back.
The constitution "didn't come out as the national compact that we thought it was going to be," the top US commander in Iraq, Gen. George Casey, told a Pentagon news conference Friday. "And that caused the situation to change a little bit."
He said he still believed some troop reductions were possible in 2006.
Iraqi and US forces were gearing up for more mayhem, increasing the number of checkpoints around Baghdad. Iraqi security forces have intelligence that 33 car bombs are ready and located somewhere in the capital, said Maj. Abdul-Karim al-Mohammedawi, of Iraq's Interior Ministry.
Iraqi troops at a checkpoint Friday captured a woman strapped with explosives under her clothes who was headed for a flea market to carry out a suicide bombing, said army Gen. Jalil Khalaf.
The discovery came after Iraq's first known female suicide bomber killed six people in a northern city on Wednesday, raising fears of a new insurgent strategy aimed at eluding checkpoints, where women often aren't stopped because of Islamic sensitivities over modesty.
In Friday's Hillah attack, a car parked in the market exploded at about 9:30 a.m. as people shopped on their day off before going to weekly Islamic prayers. At least 10 people, including three women and two children, were killed and 41 wounded, said Dr. Mohammed Beirum of Hillah General Hospital.
Hillah, about 60 miles south of Baghdad, has seen frequent attacks during Iraq's two-year insurgency -- notably a February car bomb that killed 125 people, Iraq's deadliest single bombing.
"Where are the security men? Where are the policemen?" asked a local resident. "What have the women and children done to be killed like this?"
In Balad, officials were still trying to determine the toll from three car bombs that detonated within minutes of each other in an outdoor market and two nearby commercial streets Thursday evening.
The death toll rose to 102 after some of the 150 wounded taken to a nearby US military base died. Victims included Sunni Arabs who work in the Balad market.
The Balad attacks hit a region particularly key in the referendum: a string of mainly Shia towns in Salaheddin, one of four provinces where Sunni Arabs have enough of a majority to potentially get a two-thirds "no" vote.
Under election rules, if any three of Iraq's provinces vote "no" by that margin, the constitution is rejected even if a majority across the country accepts it.
The fewer Shias in the area vote, the more likely Sunnis can reach the two-thirds mark.
Al-Qaida in Iraq issued a claim of responsibility for the Balad attack in a Web statement Friday. The statement, however, said the bombs exploded in the morning and hit Iraqi police and National Guard units. The claim's authenticity could not be verified.
"They have started using these disgusting methods to kill civilians, to scare them from the referendum," said Khalaf, the Iraqi army general.
Iraqi President Jalal Talabani, a Kurd, remained optimistic, insisting, "I think that the majority of Iraqi people, including some Arab Sunnis, will vote for 'yes' in the referendum."
Moderate Sunni Arab leaders have urged their community to reject the constitution, saying it will fragment Iraq and leave them weak compared to Shias and Kurds. The political divisions, sharpened by insurgent bloodshed, have raised fears Iraq could be plunged into civil war.
During Friday prayers at a Baghdad's main Sunni mosque, the preacher warned against violence, blaming it on foreign extremists.
"These are hideous acts. They want to destroy your country," Sheik Ahmed Hassan Al-Taha told worshippers at the Abu Hanifaa mosque, urging them to support the Iraqi military.
"Those who are tearing Iraqi bodies to pieces are not acting with courage. They want to wreck Iraq."
