A vehicle carrying people to Parachinar Friday was targeted in the attack, The News International reported.
The injured were taken to a hospital, where they were reported in stable condition.
Investigators said no arrests had been made.
At least 57 people were killed late Friday in two bombing attacks in Parachinar, in Pakistan's tribal areas, authorities said.
The first bombing hit a busy marketplace full of people shopping for the Iftar meal, which breaks the Ramadan fast. The second was at a taxi stand.
The bombings strained health services in Parachinar, a city of about 50,000 150 miles west of Peshawar. The city, close to the Afghan border, is capital of the Kurram Agency.
The agency headquarters hospital was crowded with the injured, Dawn said. Relatives brought charpoys, traditional Pakistani beds made of knotted ropes, to the hospital.
Private vehicles were used to move the injured to hospitals in other towns.