A bomb tore through a vehicle in Orakzai on Wednesday, killing 14 members of the same clan, including three children, officials said.
Eight people were killed on the spot and six died in Kohat hospital, Hussain said.
The dead included three women, two 11-year-old boys and a three-year-old girl, he said. All the victims were part of the same clan or same extended family.
"It was a militant attack, the aim was to create panic in the area by killing ordinary people," Hussain said.
Doctor Mohammad Naeem of Kohat District Hospital confirmed the toll and said that an 11-year-old boy with serious injuries was transferred to Peshawar for specialist care.