A homicide car bomber struck a governor's compound north of the Afghan capital on Monday while U.S. troops were inside, officials said. The blast killed two Afghan civilians and wounded two American soldiers.

A unit of U.S. troops from the nearby American base at Bagram were meeting with the governor, and their vehicles were parked outside the gate when the bomber detonated his explosives, said Parwan province's police chief, Khalil Ziae.

The blast killed two Afghans and wounded 15, said Ziae. U.S. Sgt. 1st Class Joel Peavy said two American troops outside the compound were among the wounded. American forces inside the complex were not harmed.

The attack came one day after 14 Afghan school children were killed when an explosives-laden truck detonated near the gates of an Afghan and U.S. military outpost.

Two bombings in the southern province of Kandahar on Monday killed three civilians and wounded 21, said Gen. Saifullah Khan, Spin Boldak's border police chief. A suicide bomber on a motorbike detonated his explosives in the border town of Spin Boldak first, and a minute later a bomb in a handcart went off nearby, said district chief Inayatullah Khan.

In neighboring Helmand province, Taliban militants attacked a police post late Sunday. Soldiers and police fought back, killing seven insurgents, said Helmand provincial police chief Asadullah Sherzad. One policeman was wounded, he said.

The bombing that killed 14 students Sunday was captured on a U.S. military security camera. The footage 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. The vehicle moves toward the 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 the children were attending a final day of class for the year to find out whether they would move up to the next grade.

The U.S. military said the attack in the eastern province of Khost killed the 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.

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 already in the country.

More than 6,100 people have died in insurgency-related violence this year, according to an Associated Press count of figures from Western and Afghan officials.