Thane district rural police said the deceased were from the same family and were residents of Rajiv Gandhi Nagar in Goregaon in suburban Mumbai.
They had hitched a ride in the tanker, which was on its way from Nashik to Mumbai. The injured were rushed to the Nashik civil hospital, while the bodies were taken to the Shahapur rural hospital for autopsy.
According to police, the tanker seemed to have skidded, hit the road-divider, and overturned. Madhav Waghmare of Shahapur rural hospital said the injured were brought there at around 2.45 AM; they were later sent to Nashik civil hospital for further treatment.