The actress was however unhurt in the incident, they said adding it happened yesterday when the actress was addressing a gathering at Refinery Nagar.
According to eye witnesses, Hema arrived late for her scheduled address and scores of people by then had queued up to see her.
The crowd then had swelled up and become unmanageable, and as soon as she arrived and started delivering her speech, a number of people ran towards the stage following which a portion of the stage collapsed, police said.