A homicide car bomber attacked a three-vehicle U.S. Embassy convoy on a notoriously dangerous road in the Afghan capital on Monday, killing an Afghan teenager and wounding five embassy security personnel, officials said.

The blast propelled one of the armored SUVs across the road, which is often the site of bombings and rocket attacks. The two other vehicles were also damaged, and flames shot through the wreckage of the suicide car bomb.

A 15-year-old Afghan on the side of the road was killed, said Hasib Arian, the district police chief.

Five U.S. Embassy security personnel were injured, one seriously, said Col. Tom Collins, the spokesman for NATO's International Security Assistance Force. The U.S. ambassador, Ronald Neumann, was not in the convoy, said embassy spokesman Joe Mellott.

A Taliban spokesman, Qari Yousef Ahmadi, said in a phone call to The Associated Press that a Taliban militant from Khost province carried out the attack.

The explosion, witnessed by an Associated Press reporter traveling behind the convoy, occurred about two miles from the embassy on the road which leads to the U.S. base at Bagram and the town of Jalalabad to the east.

• More coverage of the struggle for stability is available in FOXNews.com's Afghanistan Center.

Late last month, a homicide bomber killed 23 people outside the U.S. base at Bagram during a visit by Vice President Dick Cheney. In September, a homicide bombing near the U.S. Embassy killed 16 people, including two U.S. soldiers.

The U.S. Embassy closed down Monday and sent out a warning to Americans in Kabul, which has not seen a suicide bombing since December.

U.S. Embassy security teams initially prevented Afghan police, NATO soldiers and journalists from getting close to the vehicles.

"When I reached the bomb site, I told them, "I am the chief of district No. 9. It is my duty to investigate, let me go," said Arian. "But they didn't listen. They pushed me, they humiliated me."

In the southern province of Kandahar on Monday, a roadside bomb hit a police vehicle, killing Panjwayi district's chief of the criminal division, said provincial police chief Esmatullah Alizai.

Elsewhere in Panjwayi, a suicide bomber attacked a team of police working to eradicate poppies, Alizai said. One vehicle was damaged but no one was hurt.

Afghanistan has seen an upsurge in Iraq-style violence over the past year as militant supporters of the former Taliban regime have stepped up attacks and increasingly embraced new deadly tactics such as suicide and roadside bombings.

The Afghan government, struggling to contain the violence, also must overcome mistrust among Afghans who believe their leaders are more corrupt than the Soviet-backed government in the 1980s or the Taliban-run government in the 1990s.

According to a survey released Monday by the independent Integrity Watch Afghanistan, about 60 percent of Afghans said the current administration is more corrupt than any other in the past two decades.

Money "can buy government appointments, bypass justice or evade police," while the government is "unable or unwilling to seriously tackle corruption," it said. The group said it interviewed 1,258 Afghans for the study. It gave no margin of error.

"Corruption has undermined the legitimacy of the state," said the group's executive director, Lorenzo Delesgues.

Corruption in Afghanistan is fueled by low-paid government workers who pad their salaries by demanding bribes to process simple paperwork. Many Afghans also pay bribes to avoid trouble with police, who make about $70 a month.

The country's booming heroin trade also leads to corruption, with police and other government officials looking the other way after payoffs by farmers and drug-runners.

Even Afghanistan's anti-corruption chief, Izzatullah Wasifi, has a troubling past. A recent Associated Press investigation found he was convicted two decades ago for selling heroin in the United States.

Wasifi is adamant his drug conviction should not affect his ability to serve in government, and compares his situation to that of President Bush, who was once arrested in 1976 for drunk driving.

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