Police said the RPF personnel, a resident of Bihar, is missing. (Representational)

Three members of a family were shot dead and two injured when a Railway Protection Force (RPF) personnel allegedly opened fire on them in Jharkhand's Ramgarh district, police said on Sunday.

Ramgarh Superintendent of Police, Prabhat Kumar said RPF personnel Pawan Kumar Singh on Saturday night allegedly opened fire from his 9mm pistol on railway porter Ashok Ram and his family at their house near Barkakana railway junction.

Ram (55), his wife Lilawati Devi (52) and pregnant daughter Meena Devi (27), died on the spot while another daughter Suman Devi (25) and son Chintu Ram (20) were injured, the SP said.

The family of Ram stay at the railway barrack quarters in Barkakana police station area while the personnel is posted at Barkakana junction of the East Central Railway (ECR), Mr Kumar said.

The two injured have been referred to a hospital in Ranchi.

Deputy Inspector General of Police, North Chhotanagpur Division, Pankaj Kamboj, along with other senior police officers, visited the incident site.

The RPF personnel, a resident of Karath village in Bihar's Bhojpur district, is missing, police said.

Bittu Ram (30), another son of Ashok Ram, told visiting reporter that they run a milk business and the personnel is one of their customers.

The personnel was not given milk on Saturday as he had an outstanding amount Rs 1,200. Angered at being denied of milk, the personnel opened fire, he claimed.

Sunil Kumar Gupta, RPF inspector, said the personnel was deployed as a security aide of assistant commandant of RPF at Barkakana.

Angry locals blocked the Ramgarh-Ranchi via Pithoria highway early on Sunday demanding immediate arrest of the accused, a job for a dependent of those killed in railways and adequate compensation to the family, the police said.

They also blockaded the railway tracks for some time, affecting train services, the police added.