Smoke and flames could be seen coming out of a Braamfontein building on Melle and Jorissen street on Wednesday afternoon.
The building was being evacuated by emergency services on scene after 3pm.
This marked the third fire in the city this month.
Two other buildings that caught fire were a factory in Eloff street and the fire that saw three firefighters losing their lives last week at the Bank of Lisbon building.
Tributes poured in for the fallen heroes today as hundreds of firefighters paid their last respects outside the Bank of Lisbon building, which also housed the health department, on Wednesday morning.
Emergency services, Johannesburg Metro Police, family, and friends remembered Mduduzi Ndlovu, Khathutshelo Muedi and Simphiwe Moropana, who died last week while battling a blaze.
Firefighters, wearing their uniforms, sang and comforted each other at the wreath-laying ceremony. Some of the victims’ family members were unable to contain their emotions when they arrived at the building where their loved ones lost their lives.
Grieving relatives comforted each other, their wails piercing a sombre gospel tune played by a brass band.