Hyderabad: Actor Rana Daggubati began shooting for Hindi-Telugu bilingual "Ghazi", India's first submarine-based war film, on Thursday here. "Pushing my experimental envelope towards mainstream cinema yet again!! #GHAZI (Hindi-Telugu bi-lingual) begins filming today (sic)," Rana posted on his Twitter page on Thursday. The film is based on the true incidents on the mysterious sinking of PNS Ghazi, a Pakistan submarine during the Indo-Pak 1971 war. Actress Taapsee Pannu is paired with Rana, and she's rumoured to be playing a refugee. The film will be directed by debutant Sankalp, and it will be partially based on his own book Blue Fish. "Ghazi" will be produced by PVP Cinema. The story is about an executive naval officer of the Indian submarine S21 and his team who remain underwater for 18 days.