Photos: Car bomb in Afghanistan kills 15, including 6 Americans

A U.S. soldier arrives to the scene where a suicide car bomber attacked a NATO convoy in Kabul, Afghanistan, Thursday, May 16, 2013. A Muslim militant group, Hizb-e-Islami, claimed responsibility for the early morning attack, killing many in the explosion and wounding tens, police and hospital officials said. The powerful explosion rattled buildings on the other side of Kabul and sent a pillar of white smoke into the sky in the city's east. (AP Photo/Anja Niedringhaus) ( APTOPIX Afghanistan )

Afghan policemen walk around the destroyed suicide car bomb at the site of a suicide attack in Kabul on May 16, 2013. AFP PHOTO/ Massoud HOSSAINI/AFP/Getty Images ( 519761242 )

Afghan policemen stand guard at the site of a suicide attack in Kabul May 16, 2013. REUTERS/Mohammad Ismail ( AFGHANISTAN ATTACK/ )

Afghans comfort a man, left, who claims he has lost all his children at the scene where a suicide car bomber attacked a NATO convoy in Kabul, Afghanistan, Thursday, May 16, 2013. (AP Photo/Anja Niedringhaus) ( Afghanistan )

An Afghan fireman stands next to the debris of a car at the scene where a suicide car bomber attacked a NATO convoy in Kabul, Afghanistan, Thursday, May 16, 2013. (AP Photo/Anja Niedringhaus) ( Afghanistan )

An Afghan Army soldier is seen through the wreckage of a destroyed car after a suicide car bomber attacked a NATO convoy in Kabul, Afghanistan, Thursday, May 16, 2013. (AP Photo/Anja Niedringhaus) ( Afghanistan )

An Afghan man directs his children away from the scene where a suicide car bomber attacked a NATO convoy in Kabul, Afghanistan, Thursday, May 16, 2013. (AP Photo/Anja Niedringhaus) ( Afghanistan )

NATO soldiers with the International Security Assistance Force (ISAF) investigate at the site of a suicide attack in Kabul May 16, 2013. REUTERS/Mohammad Ismail ( AFGHANISTAN ATTACK/ )

Afghan policemen stand guard at the site of a suicide attack in Kabul May 16, 2013. REUTERS/Mohammad Ismail (AFGHANISTAN - Tags: CIVIL UNREST MILITARY) ( AFGHANISTAN ATTACK/ )

A U. S soldier secures the area where a suicide car bomber attacked a NATO convoy in Kabul, Afghanistan, Thursday, May 16, 2013. (AP Photo/Anja Niedringhaus) ( Afghanistan )

NATO soldiers with the International Security Assistance Force (ISAF) arrive at the site of a suicide attack in Kabul May 16, 2013. REUTERS/Mohammad Ismail ( AFGHANISTAN ATTACK/ )

French soldiers with the NATO-led International Security Assistance Force (ISAF) carry away the body of a victim from the site of a suicide attack in Kabul on May 16, 2013. AFP PHOTO/Daud YardostDAUD YARDOST/AFP/Getty Images ( 519763936 )

Afghan policemen stand guard at the site of a suicide attack in Kabul May 16, 2013. REUTERS/Mohammad Ismail ( AFGHANISTAN ATTACK/ )

An Afghan policeman stands guard at the site of a suicide attack in Kabul May 16, 2013. REUTERS/Mohammad Ismail ( AFGHANISTAN ATTACK/ )

A man helps a school girl at the site of a suicide attack in Kabul May 16, 2013. REUTERS/Mohammad Ismail ( AFGHANISTAN ATTACK/ )

Blood is seen on the ground at the site of a suicide attack in Kabul May 16, 2013. REUTERS/Mohammad Ismail ( AFGHANISTAN ATTACK/ )

Afghan policemen stand guard at the site of a suicide attack in Kabul May 16, 2013. REUTERS/Mohammad Ismail ( AFGHANISTAN ATTACK/ )

NATO soldiers with the International Security Assistance Force (ISAF) arrive at the site of a suicide attack in Kabul May 16, 2013. REUTERS/Mohammad Ismail ( AFGHANISTAN ATTACK/ )

A NATO soldier with the International Security Assistance Force (ISAF) stand at the site of a suicide attack in Kabul May 16, 2013. REUTERS/Mohammad Ismail ( AFGHANISTAN ATTACK/ )

A wounded Afghan woman lies at the hospital after a suicide attack in Kabul May 16, 2013. REUTERS/Mohammad Ismail ( AFGHANISTAN ATTACK/ )

Afghan men clean up the debris after a suicide car bomber attacked a NATO convoy in Kabul, Afghanistan, Thursday, May 16, 2013. (AP Photo/Anja Niedringhaus) ( Afghanistan )

Afghan and U.S. soldiers arrive to the scene where a suicide car bomber attacked a NATO convoy in Kabul, Afghanistan, Thursday, May 16, 2013. (AP Photo/Anja Niedringhaus) ( Afghanistan )

Afghan men peer through the gate of their house at the scene where a suicide car bomber attacked a NATO convoy in Kabul, Afghanistan, Thursday, May 16, 2013. (AP Photo/Anja Niedringhaus) ( APTOPIX Afghanistan )

Workers clean up the debris after a suicide car bomber attacked a NATO convoy in Kabul, Afghanistan, Thursday, May 16, 2013. (AP Photo/Anja Niedringhaus) ( Afghanistan )

An Afghan Army soldier peers through a destroyed shop window at the scene where a suicide car bomber attacked a NATO convoy in Kabul, Afghanistan, Thursday, May 16, 2013. (AP Photo/Anja Niedringhaus) ( Afghanistan )

Afghan policemen stop people from approaching the scene where a suicide car bomber attacked a NATO convoy in Kabul, Afghanistan, Thursday, May 16, 2013. (AP Photo/Anja Niedringhaus) ( Afghanistan )

Afghan security and media representatives gather at the scene of an explosion in Kabul on May 16, 2013. AFP PHOTO/ Massoud HOSSAINI/AFP/Getty Images ( 519760914 )

Afghan security and firefighters gather at the scene of an explosion in Kabul on May 16, 2013. AFP PHOTO/ Massoud HOSSAINI/AFP/Getty Images ( 519760895 )

US soldiers arrive to the site of a suicide attack in Kabul on May 16, 2013. AFP PHOTO/ Massoud HOSSAINI/AFP/Getty Images ( 519761426 )

Afghan men walk around a destroyed US military vehicle at the site of a suicide attack in Kabul on May 16, 2013. AFP PHOTO/ Massoud HOSSAINI/AFP/Getty Images ( 519761235 )

Afghan policemen walk around a destroyed US military vehicle at the site of a suicide attack in Kabul on May 16, 2013. AFP PHOTO/ Massoud HOSSAINI/AFP/Getty Images ( 519761316 )

US soldiers arrive to the site of a suicide attack in Kabul on May 16, 2013. AFP PHOTO/ Massoud HOSSAINI/AFP/Getty Images ( 519761435 )

A female US soldier stands guard in her vehicle at the site of a suicide attack in Kabul on May 16, 2013. AFP PHOTO/ Massoud HOSSAINI/AFP/Getty Images ( 519761535 )

Afghan shopkeepers look at the site of a suicide attack in Kabul on May 16, 2013. AFP PHOTO/ Massoud HOSSAINI/AFP/Getty Images ( 519761553 )

Afghan boys look on through a window near the site of a suicide attack in Kabul on May 16, 2013. AFP PHOTO/ Massoud HOSSAINI/AFP/Getty Images ( 519761580 )

Afghan men and children look on at the site of a suicide attack in Kabul on May 16, 2013. AFP PHOTO/ Massoud HOSSAINI/AFP/Getty Images ( 519761608 )

Afghan firefighters hose down a road at the scene of an explosion in Kabul on May 16, 2013. AFP PHOTO/Daud YARDOST/AFP/Getty Images ( 519764356 )