BAGHDAD - -A bomb in a sprawling Shiite Muslim neighborhood killed at least 72 people and wounded more than 135 Wednesday, highlighting the danger that Iraq could slip into unrestrained violence after U.S. combat troops leave its cities - and with the deadline less than a week away.
It was unclear who was responsible for detonating the bomb, which was hidden in a motorcycle with a vegetable cart. Some blamed Sunni insurgents from al-Qaida in Iraq or remnants of former dictator Saddam Hussein's Baath Party, but others suggested that the bombing was the result of disputes among Shiite factions.
In either case, such bloodshed represented a major challenge for Prime Minister Nouri al-Maliki. Al-Maliki, a Shiite, has asserted that Iraqi forces are ready to take on responsibility for security with limited help from the U.S. military. His government has declared Tuesday, the deadline for U.S. troops to pull back from Iraq's cities, a national holiday.
Al-Maliki has acknowledged that there will be attacks in the days ahead but insists that Iraqi forces are up to the task. Last week, the senior U.S. commander in Iraq, Gen. Ray Odierno, expressed confidence in the Iraqi army and police.
Some U.S. soldiers are expected to remain at Iraqi bases in Baghdad and other cities as advisers, but the size of the force, rules and locations are under negotiation. President Barack Obama has set August 2010 as the deadline for U.S. combat troops to leave Iraq, and under a U.S.-Iraqi security agreement signed last year, all U.S. forces are expected to leave Iraq by the end of 2011.
Wednesday's attack occurred near rows of bird cages at the entrance to the popular Myraydi market in the Sadr City neighborhood, home to 2.5 million people, a police official said. Figures on the toll of dead and wounded were provided by medical officials. The attack followed a suicide truck bombing Saturday in Taza Khurmatu, a Shiite Turkmen town in northern Iraq, which killed at least 70 people.
The drawdown of U.S. forces, coupled with national elections scheduled for January, have raised fears that with the American presence drawing to a close, bloodshed could increase as competing factions vie for control of Iraq.
In a country emerging from sectarian war, where political parties often have ties to paramilitary groups, events such as Wednesday's bombing were certain to fuel suspicion.
