It is understood that gas may have been the cause of the incident at the properties in the Chapel Street area of Bentley, near Doncaster.
The fire service, police and paramedics are at the scene where around 20 ground and first floor flats are said to have been affected.
The condition of the injured and the extent of their injuries, is not known.
A team of engineers will assess the structural integrity of the building before making a decision as to whether residents can return or require council accommodation.
News Feed from BBC News
