The deceased were on a motorbike when the sand-filled truck hit them from the rear near the Aisha Manzil area, eyewitnesses said.
The driver attempted to flee from the scene, and in doing so dragged the man’s body, which got stuck under the front part of the vehicle, for dozens of feet.
The gruesome episode was also captured by a nearby CCTV camera. Passers-by and residents of the locality, however, managed to stop the fleeing driver.
The culprit was later handed over to police, with the truck also impounded.
Traffic accidents due to heavy vehicles have long been an issue in Karachi and have caused a number of deaths.
On March 31, 2017, the provincial government barred entry of heavy vehicles in the megapolis from 6am to 11pm.
The restriction was imposed on the orders of the Sindh High Court (SHC), which had observed that heavy traffic had been claiming more lives in the megapolis than terrorism.
The ban that lasted for over a month also prompted a 10-day strike by goods transporters.
The SHC later ordered concerned authorities to specify three routes for the passage of heavy traffic through Karachi.