South African authorities say 10 people have been killed and about 40 injured in a fuel tank explosion in Boksburg, about 40 km east of Johannesburg.

According to the fire services, the tank carrying liquefied petroleum gas got stuck under a bridge near a hospital and homes on Saturday morning.

"Our personnel intervened to extinguish the fire, but unfortunately the tank exploded," said William Ntlady, a spokesman for the fire services in the area.

In this six-second footage, it clearly demonstrates the extent of the gas tanker explosion and the casualties that will likely have occurred as a result of today's #Boksburg explosion.#SouthAfrica #Gauteng #Tambo pic.twitter.com/TDpTCvYq7T

- Gurbaksh Singh Chahal (@gchahal) December 24, 2022

He added that among the injured was the driver who was taken to the hospital, noting that the death toll rose to 10 after reporting 9 earlier.

He added that half of the injured are in serious condition, while 15 people are in stable condition despite their serious injuries, noting that 6 firefighters sustained minor injuries.

Video clips circulating on social media platforms showed the moment of a big explosion and a huge ball of fire erupting from the tank under a bridge that was clearly too low for the tank to pass under.

Unbelievable scenes: 8 people died & about 50 others were injured when a gas tanker truck scraped the top of its roof, got stuck under a bridge & exploded just outside the Tambo Memorial Hospital in Boksburg today.

Driver's whereabouts unknown.

VID: Supplied #BoksburgExplosion pic.twitter.com/stc0g4Y5LB

- Graeme Raubenheimer (@GraemeRauby) December 24, 2022

The tank, which came from the southeast of the country, transported 60,000 liters of liquefied gas, used mainly in ovens and stoves.

Witness Jean-Marie Boysen described what happened as a "great concussion" in the early hours of the morning.

"Today is indeed a very sad day in our small suburb," she said - as she stood near the forensic team examining the place.

"I went upstairs for a cup of tea and saw the huge flames and thought the house was on fire," she added.