"Just shot the taj massacre of 26 11... Merely recreating it felt terrifying... Can't even imagine what the victims would have gone through," Varma posted on Twitter.
The 50-year-old director also released the first poster of his next horror film "Bhoot Returns" on the micro-blogging site today.
The poster has an illusionary image of a girl with two noses and four eyes and the blood falling down her lip.
"Poster of Bhoot returns," he posted.
The film, which will be Varma's first 3D film, is the sequel of his 2003 spooker "Bhoot" and was previously titled "Bhoot 2".
"Bhoot Returns" stars Manisha Koirala in the lead role and will hit theatres on October 12. It will also release in Tamil and Telugu.
