U.S. Vice President Dick Cheney, center, and Afghan President Hamid Karzai, left, inspect an honor guard at the presidential palace in Kabul today, hours after a suicide bomber killed and wounded some two dozen people outside the main U.S. military base where Cheney was staying. The Taliban claimed responsibility and said Cheney was the target.

BAGRAM, Afghanistan — A suicide bomber attacked the entrance to the main U.S. military base in Afghanistan today during a visit by Vice President Dick Cheney, killing at least 14 people and wounding a dozen more. The Taliban claimed responsibility and said Cheney was the target.

Cheney's spokeswoman said he was fine, and the vice president later met with President Hamid Karzai in the capital, Kabul, before leaving the country.

There were conflicting reports on the death toll. Provincial Gov. Abdul Jabar Taqwa said 20 people were killed, while NATO said initial reports indicated three fatalities, including a U.S. soldier, a South Korean coalition soldier and a U.S. government contractor whose nationality wasn't yet known. NATO said 27 people also were wounded.

It was unclear why there was such a large discrepancy in the reports.

Associated Press reporters at the scene said they had seen the bodies of at least 12 people carried in black body bags and wooden coffins from near the base into a market area where hundreds of Afghans had gathered to mourn.

Maj. William Mitchell said it did not appear the explosion was intended as a threat to the vice president. "He wasn't near the site of the explosion," Mitchell said. "He was safely within the base at the time of the explosion."

However, a purported Taliban spokesman, Qari Yousef Ahmadi, said Cheney was the target of the attack.

"We knew that Dick Cheney would be staying inside the base," Ahmadi told AP telephone from an undisclosed location. "The attacker was trying to reach Cheney."

Ahmadi said the attack was carried out by an Afghan called Mullah Abdul Rahim from Logar province.

The explosion happened near the first of at least three gated checkpoints vehicles must pass through before gaining access to Bagram.

The sprawling base houses 5,100 U.S. troops and 4,000 other coalition forces and contractors. High security areas within the base are blocked by their own checkpoints. It was unclear how an attacker could expect to penetrate the base, locate the vice president and get close to him without detection.

"We maintain a high-level of security here at all times. Our security measures were in place and the killer never had access to the base," said Lt. Col. James Bonner, the base operations commander. "When he realized he would not be able to get onto the base he attacked the local population."

It was not the first attack apparently aimed at a top U.S. official in Afghanistan. In January 2006, a militant blew himself up in Uruzgan province during a supposedly secret visit by the U.S. ambassador, killing 10 Afghans.

Ajmall, a shopkeeper, said the "huge" blast shook a small market where he has a stall about 500 yards from the base.