The Afghan Public Health Ministry said at least 95 people were killed and 158 wounded in a suicide car bombing in the capital Kabul claimed by the Taliban.
Nasrat Rahimi, deputy spokesperson for the Interior Ministry, said the attacker used an ambulance to get through one security checkpoint by telling police he was taking a patient to a nearby hospital.
He detonated his explosives at a second check point, Rahimi said.
Zabihullah Mujahid, a Taliban spokesman, claimed responsibility for the attack, which sent thick dark smoke into the sky from from the site of the explosion near the government's former Interior Ministry building.
The bombing comes just a week after Taliban militants killed 22 peope at an international hotel in the city.