An estimated 300 people were evacuated from Trade Route Mall in Lenasia, south of Johannesburg, after large sections of the building's roof collapsed during a huge downpour in the area.
Johannesburg Emergency Medical Services (EMS) spokesperson Nana Radebe said several people were reportedly injured.
"Our vehicles are on the way to the scene and we will have a better understanding of the situation once we arrive," Radebe said.
It is unclear what the extent of the injuries are.
News24 employee Maria Pillay who was on the scene said the entire top section of the popular shopping centre is flooded. She said the water had risen to her ankles.
"Most people are just frustrated - this type of thing is not supposed to happen," Pillay said while the building was evacuated. "It started raining into the movie theatre and people are now just trying to get their money back."
She said it stopped raining shortly before 17:30, which calmed most people down. "Due to the flooding it is difficult to walk, but now people are just walking around assessing the damage," Pillay said.