Johannesburg, Aug 31 : At least 52 people were killed and 43 others injured on Thursday after a massive fire ripped through a five-storey building in Johannesburg, according to the city's emergency services. In a series of tweets, emergency services spokesperson Robert Mulaudzi said multiple people were being treated and some had been transported to health care facilities, reports CNN. Meanwhile, South African state broadcaster SABC said that emergency services and firefighters are working to douse the raging inferno. The emergency services said the fire was reported at around 1.30 a.m. on Thursday. 'At this stage the cause of the fire incident is still a subject of investigations. Officials from City of Johannesburg Disaster Management have been activated to start facilitating relief for affected families,' CNN quoted the services as saying in a statement. Videos circulating on social media show huge orange flames engulfing the lower floor of a building, and scores of people who appear to have fled outside. The cause of the fire is not yet known. /IANS