The daily service from Nagercoil to Chennai Tambaram left the station at 3.50 pm on Friday. After crossing Kavalkinaru, unidentified persons hurled stones at the moving train, shattering a windowpane. Reena Annamary (67) of Kalkulam, who was seated inside, sustained serious injuries. She was given first aid at the railway station after the train reached Tirunelveli.

The train later departed Tirunelveli Junction with a 10-minute delay. Nagercoil Railway Protection Force Police have registered a case.

Inspector Suresh and police examined the spot and reviewed CCTV footage, which shows three youths near the location. Investigation is under way.