Bomb Within Earshot of Cheney Kills 23

U.S. Vice President Dick Cheney waves as he departs Sydney, Sunday, Feb. 25, 2007. Cheney has been in Australia for three days to thank one of Washington's staunchest supporters of the increasingly unpopular Iraq war, an ally that has become a rarity by offering more, not fewer, troops for Iraq and Afghanistan. (AP Photo/Mark Baker) (Mark Baker - AP)

But it appeared unlikely the bomber would have been able to reach the vice president, who was in a "very safe and secure place" roughly a mile from the blast site, said U.S. spokesman Lt. Col. David Accetta.

The bomber, Accetta said, never tried to get by any U.S.-manned security checkpoints and instead walked into a group of Afghans outside the base and detonated himself.

"To characterize this as a direct attempt on the life of the vice president is absurd," Accetta said.

Cheney's trip to Afghanistan _ on the heels of a four-hour visit Monday to Pakistan _ had not been announced in advance. Snow said he did not know whether publicity about Cheney's overnight stay at the base helped invite the attack _ after the planned meeting Monday with Karzai was postponed.

Even though reaching the front gate of the U.S. base could have been achieved with relative ease, the idea of getting through U.S. security to attack Cheney was "far-fetched," in the words of Maj. William Mitchell, a U.S. spokesman.

Nevertheless, Seth Jones, an Afghan expert at the RAND Corp. think tank, said the attack was a "stark reminder of the deteriorating security environment" in Afghanistan and was a propaganda boost for the Taliban.

"The attack also demonstrates the strength of the suicide network the Taliban and al-Qaida have in place," Jones said. "To execute such an attack on such short notice requires a well-developed network of suicide bombers and handlers that can react quickly."

Husain Haqqani, director of the Center for International Relations at Boston University and a former adviser to three Pakistani prime ministers, said the attack "does not reflect well on the Afghan government's ability to maintain security."

The bombing sends the message that the Taliban threat "is greater than the U.S. has considered it," he said.

Karzai's office said 23 people were killed, including 20 Afghan workers waiting outside the base. Twenty other people were injured, it said.

NATO said nine people had been killed, including a U.S. soldier, a U.S. contractor and a South Korean soldier, but Collins said the numbers from Karzai's office were probably "close to the truth."

AP reporters at the scene saw 12 bodies being carried in black body bags and wooden coffins from the entrance of the base _ where they were taken after the bombing _ and into a market area where hundreds of Afghans, almost all men, had gathered to mourn.