The paediatric and neo-natal units were evacuated when a fire broke out at Durban's Addington Hospital on Tuesday morning.
Marshall Security's Kyle van Reenen said the fire started on the seventh floor where the hospital's rubbish was stored.
"Three fire trucks are on scene. There were no injuries reported," he said.
Durban's fire department was unavailable for comment.
This is a developing story, which will be updated as further information is obtained.
