The incident took place in Narayanpur village in Ballia district of Uttar Pradesh, on Tuesday, July 28, during midnight.
The actors, who suffered severe injuries, are identified as 20-year-old Rupali and 19-year-old Vikas.
According to Assistant superintendent of police K C Goswami, at the time of incident, both actors were sleeping in the compound of a college, where they were shooting for the film. The area comes under Rasra Kotwali police station area.
Both were rushed to a nearby community health centre from where they were referred to the district hospital, where the condition of Rupali was stated to be critical, Goswami added.
The accused director has been identified as Ajay Kumar, who had been sore with Rupali, as she was working with Vikas against his wish.
He fled after committing the crime. Police official said that efforts were on to nab the culprit who is absconding.
While talking to a local media channel, the victim, Vikas said that it was one-sided love from Ajay Kumar, but Rupali was against to commit a relationship with him.
Vikas suffered injuries on his neck, chest, hands and legs, while Rupali suffered severe injuries on her face.