The incident occurred when a woman along with her two children were walking on railway tracks, the police said.
They were walking towards Barauni junction and were hit by the Katihar-Patna Intercity Express from behind, killing them on the spot, GRP Station House Officer(SHO) A N Dubey said.
The identity of the deceased could not be ascertained, the SHO said adding, the deceased woman was possibly more than 30-years-old and her children, a boy and a girl, were around 10 years and 12 years of age respectively.