A 22-year-old woman was killed when one of the devices which had been placed underneath her seat exploded, said Misra, general manager of the southern region for Indian Railways.
Officials said she was travelling to Bangalore, from where she was heading to her home in Guntur, Andhra Pradesh. Her relatives have been called to Chennai.
“At least two people have suffered grievous injuries and seven have minor injuries,” he told reporters in comments aired on Indian television.