KABUL, Afghanistan - A single-file line of school children walked past a military checkpoint yesterday as a bomb-loaded truck veered toward them and exploded, ending the lives of 14 young Afghans in a heartbreaking flash captured by a U.S. military security camera.

The video shows an SUV slowly weaving through sandbag barriers at a military checkpoint just as a line of school children comes into view. They walk along a pathway between the street and a wall, several of them pausing for a few seconds in a group before moving forward again. The vehicle moves toward the security camera while the children walk in the opposite direction, nearly passing the SUV when the footage ends in a fiery blast.

Photos of the bombing's aftermath showed bloodied textbooks lying on the ground beside small pairs of shoes. Afghan officials said that the children were attending a final day of class for the year to find out whether they would move up to the next grade.

Dr. Abdul Rahman, a doctor at a hospital near the blast, said that the children were aged 8 to 10.

The U.S. military said that the attack in the eastern province of Khost killed 16 people, including 14 children, an Afghan soldier and another person - likely a private security guard that Afghan officials reported killed. The U.S. said 58 people were wounded.

In an angry condemnation of the attack, President Hamid Karzai said that those who carried it out "cannot escape the revenge of Afghans and God's punishment."

The U.N. mission in Afghanistan and the NATO-led force also strongly condemned the attack.

The blast went off near the entrance to a police and army post, said Yacoub Khan, the deputy police chief of Khost. U.S. troops are also stationed inside the outpost, but no troops were wounded or killed in the attack.

In the south, a roadside bomb killed two Canadian soldiers and two Afghans working alongside them in a dangerous region of southern Afghanistan, Canada's military said yesterday.

Violence has spiked across Afghanistan the last two years, and the U.S. plans to send between 20,000 and 30,000 additional troops to Afghanistan over the next six months to reinforce the 32,000 U.S. forces now in the country. *