Two lovers on a train journey instantly conjures up the image of "Dilwale Dulhania Le Jayenge" but director Nikhil Nagesh Bhat says he wanted to tell a different kind of love story with "Kill".

The film, which released in India on July 5 to positive reviews and is still in cinemas three weeks after its release, has been billed as the most violent movie ever made in India by its producers Dharma Productions and Sikhya Entertainment.

Starring Lakshya, Raghav Juyal and Tanya Maniktala, the film's story is inspired by a train robbery that Bhat witnessed in his student days but he understands the "DDLJ" connection with trains.

"That film is so ingrained in us that whenever we think about trains, we think about romance. This is also a love story at heart but with a twist," the filmmaker told PTI in an interview.

"Kill" is set on a moving train and revolves around an army commando, who boards the train his lover is travelling in with her family. He soon realises that robbers have taken over the train and he must face off against these group of bandits as they start looting and killing passengers randomly. Bhat said he wrote the basic premise of "Kill" in 2016 based on the robbery incident that happened during his train ride from Patna to Pune in the 90s. He told a friend about the story and forgot about it only to receive a call from the friend who informed him that she had given a brief synopsis of the story to Guneet Monga and the producer wanted to meet him.

"I met Guneet and told her that it is an impossible story to make as it is all about 'vibhats ras'. But Guneet said, ‘If it is difficult, then we must do it’ and that’s how the journey began. We wrote the first draft and went to Karan (Johar)," he said.

Johar also boarded the movie just after a brief narration, which came as a major confidence boost for Bhat, who had previously made films such as "Brij Mohan Amar Rahe" and "Hurdang" and web shows "The Gone Game" and "Rasbhari".

The maximum action in those projects, he explained, would probably include a slap but "Kill" was a challenge as it revolved around a man who transforms into a killing machine during when things go south.

Having Sikhya and Dharma as backers helped find the right people to execute his vision for the movie.

"It was my first action film and I was trying to ensure that when the audiences see it, they feel like they are on the train as passengers and going through the tragedy. It was an important challenge and everything hinged on that because if I manage that, I will involve them in the story and its emotions," he said.

The action in the movie had to be designed in a way that it captured the "contained pressure cooker" like situation inside the confined space of a train compartment.

"You cannot change the setting or location so the only thing you can change is the way each killing is depicted. During the writing phase, I would wake up and imagine myself as the protagonist and his adversaries and ghost fight in those scenes before writing them. I wrote each and every kill so that when my action choreographers come, they, at least, have a blue print to build upon," he said.

The film premiered at the Toronto International Film Festival's Midnight Madness section to positive reviews last year.

Asked about the violence in the movie, Bhat said while the film is "gory and full of action", the portrayal makes it different from a regular revenge drama.

"I have actually shown the consequences of violence and how it brings pain and agony no matter which side you are on. We become so dehumanised with violence sometimes and feel the need to glorify it but I have tried to go the other way and not glorify it at all. It is very important to look at it not with bravado or swagger," he said.

Praising the relative newcomers at the heart of the story -- Lakshya in his debut film as Amrit, host-comedian Raghav Juyal as the antagonist Fani and actor Tanya Maniktala as Tulika -- Bhat said the three actors held his hand throughout the difficult process of directing the movie.

Lakshya was the first to come on board as the filmmaker was impressed by the way he responded to the story that he didn't even want to meet other actors who were supposed to audition for the role.

"A lot of times, you go by instinct and my instinct told me, ‘He is the guy’. He is two people -- a lovelorn person and the monster killing machine when things go south... I am so glad he said yes and we have become good friends in the last four years," he said.

Fani, the antagonist, played by Juyal, was a more challenging character to cast and Bhat met more than 100 people but without much success.

"I am from Patna... I have seen people around me who look gentle but then you get to know that the friendly guy you met moonlight as a bike snatcher. You wouldn't know this when you talked to the person. So, Fani should not look like a criminal or have a scar or any other identifiable marks," he said, adding that Juyal understood the quicksilver nature of the character and aced it in the audition tape that he sent to him.

Maniktala was someone that Bhat wanted to work with since he spotted her in Mira Nair's "A Suitable Boy".

"She has such expressive eyes and I wanted to cast her. Actually, I cast all the three actors for their eyes," he said.

Bhat is happy that "Kill", which has made over Rs 20 crore at the box office, has done well as it is important for him that his movies do good business.

"The kind of faith my producers had shown in me and the script is fabulous. They decided to support me fully only on the basis of the script as I have never done action. It is important that the film earns money. I also want awards," he said.

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