Two suicide bombers killed 120 people and wounded more than 200 in the Iraqi cities of Kerbala and Ramadi today in Iraq's bloodiest day for four months.
Seven US soldiers were also killed in two separate attacks; another three bombs exploded in Baghdad, two of them detonated by suicide bombers; and insurgents sabotaged an oil pipeline near the northern city of Kirkuk, causing a huge fire.
Coming a day after 58 people died in a wave of bombings and shootings, the latest bloodshed appeared certain to ratchet up tension between Iraq's Sunni and Shia Muslims.
Kerbala is one of Shia Islam's holiest cities while Ramadi is a Sunni Arab stronghold and a hotbed of the insurgency. A suicide bomber detonated an explosive belt laced with ballbearings and a grenade, killing 50 and wounding 138 at a market within sight of the golden dome of the Imam Hussein shrine, one of the holiest sites in Shia Islam.
The US death toll is the highest on any one day since the December 15 election.
More than 240 people have been killed and 280 wounded in the five days since the New Year started, a death toll comparable with some of the nation's bloodiest weeks since the US-led invasion in March 2003.
"These groups of dark terror will not succeed through these cowardly acts in dissuading Iraqis in their bid to form a government of national unity," President Jalal Talabani said.
Television pictures showed pools of blood in the street, which was littered with debris. Passers-by loaded the wounded into the backs of cars and vans, and one black-clad woman stood crying while clutching her dead or wounded baby to her chest.
Five US soldiers died in Baghdad when a roadside bomb hit their vehicle and two were killed near the southern city of Najaf when a similar device destroyed their Humvee, killing two civilians and wounding seven, including three US soldiers.
Devices also exploded in Baghdad, although with less impact.
Three car bombs, two of them suicide attacks, rocked the capital in quick succession, suggesting a level of coordination that may be a response by Sunni Arab insurgents to the largely peaceful parliamentary election.
The bombs killed two people and wounded six, police and Interior Ministry sources said.