A woman and her two children were mowed down by an outstation train between Asangaon and Atgaon stations on the Central Railway line early on Thursday.
The three remained unidentified till Thursday evening.
According to railway police, the incident took place around 5.30 am on Thursday when the woman, who appears to be in her thirties, was crossing the tracks with her two daughters, both below five years.
They were hit by the Mumbai-bound Devgiri Express, a railway official said. The bodies have been taken to a nearby hospital for post-mortem.
The Kalyan Government Railway Police (GRP) have taken an accidental death report in the matter and are trying to identify the deceased, an officer said.