Ministry Spokesman Wahidullah Mayar said the wounded were trickling into city hospitals after the huge explosion.
A powerful blast struck downtown Kabul early today, killing at least three people and wounding 112 others, the health ministry said, adding that the toll was expected to rise.
Deputy Interior Minister Mohammad Ayoub Salangi said the blast was caused by a car bomb but the target was not immediately clear.
"Three people were killed and 112 wounded people were brought to hospitals," said health ministry spokesman Wahidullah Mayar.
"The wounded included children are trickling into city hospitals... the casualty toll is expected to rise."
No group immediately claimed responsibility for the attack, which comes as the Taliban intensify their summer offensive despite a bitter power transition within the militant movement.
Taliban insurgents killed nine people in multiple attacks on police targets in southern and eastern Afghanistan on Thursday, in their first major assaults since last week's announcement of leader Mullah Omar's death.
The attacks highlight growing insecurity amid a faltering peace process with the Taliban as Afghan forces face their first summer fighting season without full NATO support.