However, prima facie it is a case of suicide, Sohagpur police station inspector Rajendra Burman said.
The deceased were identified as Kailash Kushwaha(37), his wife Radha (35) and their two kids - Riya (3) and Mahi (1). The motorcycle they were plying on has been recovered from the spot, he added.
The circumstantial evidence suggest that Kailash and Radha, who worked as labourers, along with their kids jumped before the moving train, Burman said, adding investigations are underway.
The bodies have been sent for post mortem, she added.