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A bomb exploded near a taxi carrying women and children in the southern city of Kandahar on Thursday, killing at least five people and wounding 32, while visiting Secretary of State Condoleezza Rice (search) said the United States erred by not doing more for Afghanistan after the Soviets withdrew in 1989.

Police blamed Taliban-led militants for the attack that hit the passing taxi, a roadside restaurant and other bystanders in downtown Kandahar (search), but a purported Taliban spokesman denied responsibility. Rice was in the capital, Kabul (search), about 280 miles to the north, at the time.

The attack broke a relative lull in violence in Afghanistan and could shake U.S. military confidence that the resistance by Taliban militants is fading.

President Hamid Karzai condemned the attack as a terrorist act by "enemies of Afghanistan," but insisted security was improving. However, he said Afghan parliamentary elections originally scheduled for May will be delayed until September, nearly four years after the fall of the Taliban regime.

Rice said the United States would support Afghanistan as it prepares for the vote and called its re-emergence from years of war an inspiration.

"We will stand by the Afghan people as they go through the next stage in their democratic development, the parliamentary elections that will take place this fall. We look forward to continuing to help in the reconstruction of Afghanistan," she said.

The United States has about 17,000 forces hunting Al Qaeda (search) and Taliban rebels in southern and eastern Afghanistan. Kandahar was the main stronghold of the hard-line Taliban regime before it was ousted in a U.S.-led offensive in late 2001 for sheltering Al Qaeda leader Usama bin Laden (search).

American forces in Kandahar helped cordon off the area around the attack in a busy commercial district. Shoes and turbans of the wounded were scattered on the bloodstained street, along with the wreckage of the taxi, a three-wheeled tuk-tuk and two motorbikes.

Mullah Hakim Latifi, who claims to speak for the Taliban (search), denied the movement was behind the attack. In a phone call to The Associated Press, he described the victims as "innocent people of Afghanistan."

About two hours before the bombing, a land mine went off six miles west of Kandahar, breaking the window in an international aid agency vehicle, police chief Khan Mohammed said. No one was hurt; the aid agency was not identified.

The parliamentary vote had been slated for May but the United Nations and the Afghan electoral commission have been grappling with a lack of census data and how to register thousands of returning refugees.

"The preparations are going on and now they told us, the commission chairman, that the elections will be held in September," Karzai said during a news conference with Rice at his Kabul palace. "The Afghan people are waiting very eagerly to send their members to parliament."

Observers have long said the election, initially scheduled along with a presidential ballot last year, would be put off because of the huge task of organizing it. The election also is supposed to produce district and provincial assemblies.

Afghanistan adopted a new constitution early in 2004 and successfully held the presidential vote in October, despite worries over violence. The parliament vote is seen as the next step in the country's democratic re-birth after a quarter-century of conflict.

Rice, making her first visit to Afghanistan, said the United States made a mistake by losing its focus on Afghanistan following the Soviet withdrawal in 1989. The country plunged into years of civil war after the withdrawal, allowing the hardline Taliban to take power and turn the country into a safe haven for bin Laden and Al Qaeda.

"We have a long-term commitment to this country," Rice said.

"We learned the hard way what it meant to not have a long-term commitment. After the Soviet Union left I think it is well understood that we did not remain committed, and I said to the president earlier that in many ways Sept. 11 was a joint tragedy of the Afghan and American people out of that period."

Rice also said the country's booming illegal narcotics industry was a "serious problem," but it was being tackled through a U.S.-backed crackdown on opium poppy farmers and smugglers and with millions of dollars in aid to promote alternative crops.