The Mumbai police have stepped up the security of Bollywood superstar Salman Khan after he received a threatening e-mail, which had led to cops earlier registering an FIR against gangsters Lawrence Bishnoi and Goldy Brar, an official said on Monday.

According to the official, two Assistant Police Inspector (API)-rank officers and eight to ten constables will be part of Khan's security detail round the clock.

Also, fans will not be allowed to assemble outside the 57-year-old actor's residence-cum-office in Galaxy Apartments in suburban Bandra, he said.

Khan was earlier provided with Y plus category security by the police and he moved around in a bullet-proof car along with his personal security guards.

Now, the police have taken additional security measures for the safety of the 'Dabangg' actor, the official said.

On Saturday, the Bandra police registered an FIR (first information report) against three persons -- gangsters Bishnoi, Brar and one Rohit -- for allegedly sending a threatening e-mail to Khan's office.

The FIR was registered on the basis of a police complaint lodged by one Prashant Gunjalkar, who according to cops, frequently visits the Bandra-based residence of the popular filmstar and runs an artist management company.

When Gunjalkar was present in Khan's office on Saturday afternoon, he noticed an email had come from the ID "Rohit Garg", the official said quoting the FIR.

The e-mail stated Khan must have seen the interview given recently to a news channel by Bishnoi, and if not, he should see it. Addressing Gunjalkar, it said if Khan wants to close the matter, he should talk face-to-face with Goldy bhai, adding "there is still time but agli bar, jhatka dekhne ko milega" (next time he will receive shock).

The FIR was registered under sections 120-B (punishment for criminal conspiracy), 506-II (punishment for criminal intimidation) and 34 (common intention) under the Indian Penal Code.

An interview with Bishnoi was broadcast recently by a private news channel. Bishnoi, currently lodged in a Punjab jail, and Goldy Brar are accused in the murder of singer Sidhu Moosewala.

Notably, in June 2022, an unidentified person had threatened Khan via a handwritten note.