According to details, the incident took place when a tyre of an oil tanker burst causing vehicles on the highway to crash each other.
Fire broke out in the oil tanker following the road crash which engulfed several vehicles. A trailer carrying cars to upcountry was among the vehicles that caught fire.
Rescues workers and fire tenders arrived at the scene following the accident.
Two burnt dead bodies found from a vehicle, while four injured were transferred to hospital for medical attendance, rescue sources said. An injured succumbed to his injuries in hospital.
The traffic has been halted at Super Highway after the incident resulting in massive traffic jam at the road leading to Hyderabad from Karachi. A long queue of the vehicles witnessed on the road leaving several public transport vehicles stranded at the highway.
The fire tenders facing problems in extinguishing the fire due to the traffic jam, succeeded to douse the fire after hours long struggle.
Chief Minister of Sindh has taken notice of the incident and directed the I.G. Police Sindh and Commissioner Karachi to extend help to the people affected in the incident.