The car was packed with explosives near the house of the former head of the provincial council, Didar Lawang.
They were caught 10 minutes from the Pakistan border
Authorities said the blast was so severe they couldn't identify the victims.
A spokesman for the Taliban said its fighters were not involved.
She was engaged in a shootout with the Taliban for an hour alongside her 12-year-old brother.
One of the journalists behind a damning report says the Defence Force has never once agreed to an interview.
"We have lost them and nothing can bring them back."