The NATO-led ISAF in Kabul confirmed that the attack was against one of its military convoys.
Taliban spokesman Zabiullah Mujahid took responsibility for the attack and said it had been carried out by Hadayatullah, a resident of Kabul. He claimed 13 Italian soldiers were killed in the blast.
The explosion destroyed at least five cars and damaged buildings on both sides of the road. The blast occurred some 300 metres from the US embassy in Kabul.
Earlier this month, a Taliban suicide bomber detonated his explosives-laden vehicle close to a NATO convoy near the military base at Kabul airport, also in the eastern part of the city, killing several civilians.