Two motorcycle-borne assailants opened fire at Film City in Mumbai's Goregaon on Friday, about "20 feet" from the spot where Amitabh Bachchan was shooting.

The 2pm firing left the owner of a security agency critically injured. Raju Shinde, an office-bearer of Shiv Sena's film wing Chitrapat Sena, was sitting in a chair under a tree when the assailants shot at him.

Shinde was taken to Nanavati Hospital, where his condition was said to be stable. He took two bullets, one in the abdomen and the other on the right hand (PTI picture shows police officers inspecting the spot where the firing took place).

Shinde's security agency provides guards for film shootings.

Immediately after the firing, Bachchan tweeted that one person had died in the incident that took place 20 feet away.

Later, he clarified that the person was not killed but injured. "Correction: in gang shoot out where I was shooting in Film City person shot at is NOT dead. He has been taken to hospital," Bachchan's tweet said.

Mumbai police have formed four teams to arrest the assailants. The crime branch, too, has started a parallel investigation.

"We have formed four teams to nab the assailants and we are sure we would catch them very soon," the additional commissioner of police, Fateh Singh Patil, said.

"We have seized the motorcycle. It seems it was not stolen, so we are hopeful of getting vital leads soon," the officer added.

Asked if Shinde was facing a threat to his life as he had reportedly sought police protection in January, Patil said: "Our investigation is on and would include all possible angles."

Shinde's lawyer Sushan Kunjuraman said he had written to Mumbai police on his client's behalf in January.

"Shinde had written to Mumbai police saying he had received threats from two persons - Khalid Khan and Anwar Sayyed," Kunjuraman said.

Report by PTI