The blast happened around 12:30pm in Patani village of the provincial capital, Sharana, said Shah Mohammad Aryan, a spokesman for provincial police.
Police chief of Paktika’s Mata Khan district, Abdul Wadood Andar was the target of the attack, but he escaped unhurt, Aryan said.
Two civilians, including a child, were killed in the blast.
The police commander’s three guards were wounded.
There was no immediate claim of responsibility for the bombing.