The woman, in her 30s, has reportedly suffered injuries on her head and legs. She has been admitted at Sadar Hospital in Ara, district headquarters of Bhojpur, around 50 kilometres from Patna.
The accused, an army jawan named Ramesh Kumar, was held by an official from the Assam Rifles, who was also travelling in the train, the UP Dibrugarh-Delhi Brahmaputra Express. He was reportedly dragged from the toilet in the train and handed over to Railway Protection Force (RPF) at the next station at Buxar, police sources said.
The Railway Police has lodged two FIRs, one each at Ara and Buxar, against the accused.