At least 63 people were killed and 43 others injured after a massive fire broke out in a multi-storey building in the central business district here in South Africa's biggest city, Emergency services said on Thursday.
Authorities said it was unclear what sparked the blaze at the five-storey building in the city centre.
City of Johannesburg emergency services spokesperson Robert Mulaudzi said firefighters were alerted to the fire in a building on the corner of Delvers and Alberts streets at about 1:30 am.
"It's a five-storey building which caught fire in the early hours of this morning. We managed to evacuate the people who were inside the building as soon as we arrived while we were conducting firefighting operations," TimesLIVE newspaper quoted Mulaudzi as saying.
The fire gutted the building on the corner of Albert and Delvers Streets.
"63 bodies were recovered and 43 were injured...still continuing with search and recovery operation," Mulaudzi posted on X, formerly known as Twitter.
A video posted by Mulaudzi on X showed fire trucks and ambulances outside the building with burnt-out windows.
A toddler was among the deceased.
Of the injured, some suffered smoke inhalation with others sustaining minor injuries.
Mulaudzi said the fire had been contained and that they were busy with "damping down" as well as search and recovery operations.
He said the death toll may increase because there was an informal settlement inside the building which may have resulted in people being trapped while trying to flee.
"Every floor has an informal settlement, and those that were trying to evacuate were trapped because of the structures between the floors," the News24 website reported.
"There is a huge possibility that the body count could be over 60 because we are going from floor to floor.
"We have informed people who are at the scene looking for their relatives that chances of finding them alive are very slim."
Those injured in the blaze were taken to hospital.
Officials from the City of Johannesburg disaster management have been activated to start facilitating relief for affected families.