The explosion occurred in the Baghranian area in Nahr-e-Saraj district after a civilian vehicle struck the device, Khaama Press reported.
Omar Zwak, a spokesman for the provincial governor, said five people, including two women, were injured in the blast.
Zwak blamed the bombing on Taliban insurgents.
Notable deaths of 2014 [PHOTOS]
China overhauls legal system, at least on paper