The homicide bomber rammed his explosives-filled car into two Italian military vehicles about midday, Italian Defense Minister Ignazio La Russa said in Rome. He said six of those aboard were killed and four wounded.
Taliban spokesman Zabiullah Mujahid claimed responsibility, saying in a text message that they had ordered had carried out the homicide attack against foreign forces.
The explosion shattered windows in buildings about half a mile away and shook offices and homes throughout the central Afghan neighborhood that houses a number of embassies and military bases.
Charred vehicles littered the area around the blast site -- a road just off a main traffic circle that leads to the airport. An Associated Press reporter saw at least six vehicles burned, including an Italian Humvee, and two burned bodies that were later covered with plastic sheets.
Defense Ministry spokesman Gen. Mohammad Zahir Azimi said at least 10 Afghan civilians were killed and 52 wounded.
Shopkeeper Feraudin Ansari said he felt the blast in his store about 50 yards from the site. Windows were broken in all the shops on the street. He said he was angry at NATO forces for patrolling in downtown areas.
"Why are you patrolling inside the city? There is no Al Qaeda, no Taliban here," 25-year-old Ansari said. "My shop is destroyed and my head hurts from the blast."
The explosion was the fourth major attack in the capital in five weeks.
In the latest, a car bomb exploded Sept. 8 near the entrance to the military airport in Kabul in an attack on a NATO convoy, killing three civilians. The Taliban claimed responsibility for the blast.