Bollywood star Saif Ali Khan found himself in trouble Monday after the Government Railway Police (GRP) registered a case against him and four others of a film unit for allegedly assaulting a photojournalist.

Khan and members of the unit of his latest film "Three Idiots" were booked for assault, intimidation and inciting violence.

GRP officials said the move followed a complaint by a photojournalist from a Hindi newspaper who said he had been beaten up by the film unit staff after being incited by Khan.

The photographer was taking pictures of Khan at the railway station here Sunday. The star objected and told private security and film production unit associates to tackle the photojournalist following which he was allegedly thrashed.

"We will arrest him soon," GRP inspector general G.J.S. Grewal said here.

The registration of the case follows protests by media persons against Khan and others.