Actor Vivek Oberoi fractured his leg and director Mani Ratnam got pain in the chest on Wednesday after a stunt scene they were shooting on the Vidyasagar Bridge over the Hoogly River in Kolkata went awry.
Co-stars Abhishek Bachchan and Ajay Devgan, standing close along with Ratnam, received minor injuries during the accident, which led the production unit to abandon the shooting of the yet-to-be-titled film for the next few days.
Ratnam also received minor bruises on his hand.
Oberoi fractured two bones of his left leg, according to Mala Chatterjee, medical superintendent of the Calcutta Medical Research Institute, where the star was admitted.
The medical superintendent said the condition of the actor was 'serious' and he would undergo surgery on his fractured leg on Thursday.
The surgery will be conducted by two Dr Ashok Das and Dr Subrata Dasgupta, she added.
Abhishek Bachchan and Ajay Devgan later went to the B M Birla Heart Research Institute to see Ratnam. 
The accident took place at around 1715 IST.
"The scene involved Oberoi running through several stationary vehicles and a motorcycle chasing him. The bike was being ridden by a stuntman. In the film it was to be Ajay Devgan on the bike," a police official told rediff.com.
As Oberoi fell down, the motorcycle, which followed him closely, ran over his left leg.
"Seeing the accident happen in front of his eyes, Mani Ratnam, who was taking the shot from up close, yelled and passed out," the official said.
