The overnight blaze ripped through a five-storey rundown building in the city centre occupied by homeless people and squatters. Dozens were injured.

The building was among many in the downtown area that have been abandoned and “hijacked” by criminal gangs who rent them out to families.

Sadness and grief

The fire was among the worst in South Africa’s history. President Cyril Ramaphosa, who visited the site, described it as a “tragedy” and “a wake-up call”, according to media reports.

The UN Secretary-General was deeply saddened by the news, his spokesperson said in a statement issued later on Thursday.

“In this moment of great sadness and grief, he conveys his sincere condolences to the families of the victims and to the Government and people of South Africa,” it said.

Mr. Guterres also wished a prompt recovery to the injured.

He added that the UN Country Team in South Africa stands ready to work with the authorities to provide assistance to those affected by the fire, and to prevent further incidents of this nature.