BAGHDAD, Iraq — BAGHDAD, Iraq -- Insurgents set off a pair of car bombs in a crowded Baghdad marketplace yesterday, killing at least 88 Iraqis in a warning sign that Sunni militants will challenge the proposed U.S. playbook to calm the country's sectarian violence.
The increase in Sunni violence has exposed a weakness in the U.S. and Iraqi effort to stabilize Baghdad. The Bush administration, which is sending 21,500 more troops to Iraq, has vowed to pacify Shiite militias thought to be targeting Sunni Arabs.
But Sunni attacks on Shiite targets have continued unabated, threatening to strengthen the Shiite population's support of its militias and jeopardizing efforts to clear breathing space for vital reconciliation talks between factions. Bush is expected to outline and promote his plan for securing Baghdad during his State of the Union address tonight.
The explosions left behind gruesome scenes of chaos in the city's Tayaran Square, often a frenzied crossroads of commerce and traffic. The wounded dragged themselves into taxis past mangled vendor carts, blackened debris and piles of soot.
Dazed survivors prodded bodies for signs of life and bandaged the living with secondhand clothes from thrift stores at the market. The smell of burned flesh hung in the air hours after the explosion.
At least 168 Iraqis were wounded in the attack, which bore sectarian overtones and was similar to bombings by Sunni insurgents, particularly those with ties to foreign extremist networks. Most of the business people and workers in the capital's downtown marketplaces are Shiites.
Victims of the bombing cursed the government of Prime Minister Nouri al-Maliki as they hauled away bodies and debris.
"Where is Maliki now?" cried one man, whose brother was killed in the blast. "We are being killed and they are sitting on their fancy chairs."
Another car bomb explosion near fruit and vegetable stalls in the mostly Shiite town of Khalis, 60 miles northeast of Baghdad, killed at least 12 Iraqis and wounded 40. Authorities also found the bodies of 29 men, apparent victims of Shiite death squads, scattered around Baghdad.
At least one U.S. soldier was killed and four wounded in a roadside bomb attack in predominantly Sunni Nineweh province.
At least 30 U.S. troops have died in Iraq since Friday, amid a surge in apparent Sunni attacks, including a well-coordinated attack Saturday in Karbala in which uniformed men stormed a security compound and killed five American soldiers.
Frederick Kagan, a military analyst at the conservative American Enterprise Institute in Washington, said the recent attacks on U.S. forces could be a reaction to new operations in Baghdad or retaliation for a recent battle on Haifa Street, in which American forces killed Sunni insurgents.
But militants also could be launching an all-out effort to discourage the United States from sending more troops, Kagan said.
"Some insurgent group could be trying to mass against us to inflict casualties as a way of turning the surge off," he said.
Yesterday's blasts took place less than a mile and a half across the Tigris River from the U.S.-protected Green Zone. Pedestrians and shopkeepers had rushed to aid victims of the first explosion when another powerful blast shook the ground.
Witnesses were baffled by the attack's apparent target, which appeared to be a group of stalls selling cigarettes and produce. Some witnesses said the first blast was caused by a suicide bomber who drove a Volkswagen into a popular cafe.
The owners, vendors and laborers in the market tend to be Shiites, a legacy of centuries of Sunni domination of government jobs and the civil service that forced Iraqi Shiites, Jews and Kurds to turn to private-sector employment, especially in the capital.
In other violence, gunmen shot and killed a Sunni tribal leader in western Baghdad and a police academy trainer in eastern Baghdad. Mortar fire struck a Shiite enclave in southern Baghdad and a Sunni section in the western part of the capital, killing four and wounding 11.
Gunmen kidnapped Khalid Fenjari, mayor of the provincial capital of Baqouba, which in recent weeks has been torn by sectarian warfare. The gunmen blew up the mayor's headquarters after abducting him.
Borzou Daragahi writes for the Los Angeles Times.