According to the police, people from nearby areas were collecting fuel from the oil tanker which had skidded off the highway and overturned in Bahawalpur city's Ahmed Pur Sharqia area, reports The News International.
Over 100 others were injured. They were moved to Bahawalpur Victoria Hospital and other health facilities.
The toll may increase as many of the injured are said to be in critical condition, the police added.
Two fire engines battled the fire and eventually gained control over it.
Six cars and 12 motorcycles parked in the vicinity were also severely damaged.