A major fire broke out at the set of Adipurush, a film starring Prabhas and Saif Ali Khan, in suburban Goregaon on Tuesday afternoon.
A fireman sustained minor injuries, officials said, adding that the blaze was doused by late evening.
Khan and Prabhas were not present when the incident took place.
Akshay Tarte (24), the injured fireman, was taken to a private hospital and discharged later.
The film went on floors on Tuesday with a special set erected on open ground near Inorbit Mall in Bangur Nagar.
The fire started around 4.10 pm, a police personnel said, adding that eight fire engines and six water tankers were rushed to the spot.
A source said director Om Raut and a small crew were filming on the set.
"Prabhas and Saif were not present," he added.
Fire brigade officials declared it to be a "level two" blaze, which is considered as major.
It is reported that the mishap occurred due to a short circuit. According to sources in the studio, the fire was brought under control soon enough and nobody was injured. No casualty has been reported.
Unconfirmed videos from the burning set of the film have gone viral on social media, with netizens expressing their concern over the unfortunate incident.
"Fire caught on the sets of #Adipurush at a Goregaon studio #Mumbai. Everyone is safe no one has come under any physical harm. It happened due to short circuit and the entire chroma set up went into ashes. #Prabhas and Saif were not a part of this shoot," photographer Viral Bhayani wrote on Instagram.
Earlier in the day, Raut had announced on social media that he has begun with the mahurat shot for the film.
Prabhas officially announced the beginning of shoot on Tuesday morning with the word "Aarambh" (start) via his Instagram account.
Featuring an extensive range of visual effects, Adipurush is an on-screen adaptation of Ramayana, and features Prabhas as Lord Ram and Khan as Lankesh.
Backed by T-Series, Adipurush is described as a film celebrating "the victory of good over evil."
The film is Raut's follow-up project to his blockbuster movie Tanhaji: The Unsung Warrior, starring Ajay Devgn and Khan, which released last year.
Adipurush is slated for release in theatres on 11 August 2022.
(With inputs from agencies)