"We have information that 126 people have been killed in the explosion inside the military training center," a senior defense ministry official told Reuters.
A provincial official also said the death toll was over 100.
A government spokesman declined to comment. Earlier the government said 12 people had been killed.
According to Afghanistan’s Pajhwok News, a Taliban suicide bomber drove a car bomb into the base following a firefight between the militants and security forces.
The attack took place shortly after 8am on Monday.
