A 25-year-old woman lost an eye and had her face disfigured when an unidentified person threw acidic substance at her on a Mumbai railway platform in the morning on Thursday.
Preeti Rathi's father and aunt and three others were also injured.
The Government Railway Police (GRP) said the suspect had been travelling in the same train and was carrying at least a litre of what is suspected to be sulphuric acid.
The accused targeted Rathi after she, along with her father, uncle and aunt, got off the train.
"The accused followed her and patted her shoulder. The moment she turned, he threw acid on her face and fled," said B Shirsat, deputy commissioner of police, GRP.