American soldiers stand guard at the site of a suicide bombing near the main gate of the Kandahar Air Field in southern Afghanistan.
Seven civilians, including two children, were killed in the blast, and eight people were wounded.
(SOUNDBITE) (Pashto) BAHARDAR KHAN, TRUCK DRIVER AND EYEWITNESS, SAYING:
"I was standing here near my truck. I saw a Corolla car driving very fast toward the gate. The car blew up near the American convoy leaving the base then I saw smoke and dust coming up and the American convoy on fire, I don't know anything more."
No-one had yet claimed responsibility for the attack, which comes as foreign forces fighting Taliban-led insurgents are in the process of handing over security to the Afghan army and police.
Despite the presence of more than 100,000 foreign combat troops - due to leave the country by the end of 2014 - the U.N. says violence in Afghanistan is at its worst levels since the Taliban were toppled in 2001.
Nick Rowlands, Reuters.
