Ambulances and police cars rushed through the early morning traffic in the Chihulsutoon area south of Kabul to the site of the terrorist attack that also left at least 20 soldiers and civilians wounded.
It is the second suicide attack in the capital in the last two days and it coincides with U.S. Defense Secretary Robert Gates' two-day visit to Afghanistan.
On Tuesday, a similar attack on a NATO convoy heading from Kabul airport to the U.S. Embassy wounded at least 20 civilians. Taliban militants took responsibility for both attacks.
Gates arrived in Kabul on Monday to assess the rising level of violence, which is hampering the progress of peace in the Central Asian country, torn apart by a civil war.
According to the Associated Press, Taliban militants launched more than 133 suicide attacks in 2007 and at least 6,200 people have died in insurgency-related violence in Afghanistan since the beginning of the year.