The incident occurred in the state of Orissa, some 120 kilometers (74.5 miles) north of the city of Bhubaneswar, while the Coromandel Express was travelling to Chennai, on the southeast coast of the country.
Around 14 of the train's 24 coaches were initially reported to have derailed. Three of the coaches were completely wrecked, officials said. Other media reports said some 18 coaches had derailed.
The death toll could rise further as many passengers are still trapped. Most of the injured passengers are in a critical state.
The cause of the accident is being investigated.