A 53-year-old woman sleeping inside a rail compartment with the strap of her bag wound around an arm for safety was dragged out of her berth and thrown off the express train by a robber furiously tugging at it.

Krishna Das, a resident of Haridevpur on the southern fringe of Calcutta, was returning from a pilgrimage to Varanasi aboard the Anand Vihar-Howrah Superfast Express when she found herself in the middle of a train nightmare come true early on Monday.

The homemaker, who was part of a group of 25 middle-aged and elderly people travelling together in the S2 sleeper compartment from Allahabad, lost some cash and valuables but was lucky to be alive after falling off the moving express train and landing hard beside the tracks close to Dhanbad.

She needed stitches to close a gash on her head and injured her right hand and left eye. "These injuries will heal but I will probably never recover from the trauma," she told Metro on Tuesday.

Krishna had been forewarned about robbers targeting sleeping passengers' luggage on the Jharkhand stretch of the route and so had wound the strap of her bag around her right arm before trying to sleep.

"I was holding on tightly to my black leather bag containing Rs 3,000, two mobile phones and a digital camera, among other things. Sleep eluded me until around 4.30am," she recounted.

Krishna thinks she fell asleep "for a brief moment" in berth 79 after the train resumed its journey following a brief stop at Dhanbad station.

"I woke up to a tug at my hand. As I opened my eyes, there was this man who seemed to be in his mid-thirties standing there and pulling my bag. Since the strap was around my right hand, the man failed to take it away. He dragged me till near the door even as I tried to resist him," Krishna said.

The 53-year-old found herself fighting a losing battle against a much stronger person even as she held on to anything she could lay her left hand on and screamed for help. "Most of the passengers were sleeping and possibly nobody realised that a robber had dragged me near the door to one side of the compartment. They woke up on hearing my screams, but I was out of the train and lying helpless beside the tracks before they could come to my rescue."

The robber fled with the bag the moment her grip loosened after the fall. Krishna said she felt a sharp pain in her head and right hand as she lay there, trying hard not to lose consciousness.

"It was still pitch dark and the sides of the rail tracks were covered in thickets. I had almost given up hope when I saw the train stop nearly five hundred metres from where I was," Krishna said.

She would learn later that the other members of her group - all of them part of an informal yoga club called Pranayam Parivar - had pulled the chain to stop their train. Some of them alighted and ran back the entire distance to where Krishna was and carried her back into the train.

"She was bleeding from the head injury and was in a semi-conscious state. We took her to the railway dispensary at Asansol station, where she was administered first aid," said 64-year-old Saradindu Ghosh, an advocate.

He lodged a complaint with the Government Railway Police post at Asansol station on Krishna's behalf. "She was not in position to write down a complaint."

Krishna was admitted to Howrah District Hospital after the train arrived at Howrah station in the morning.

"We have received a complaint from one Saradindu Ghosh, in which he has stated that his co-passenger Krishna Das was thrown on the tracks after the Anand Vihar-Howrah Superfast left Dhanbad station. We have forwarded the complaint to Dhanbad GRP for investigation," a railway police officer in Asansol confirmed to Metro over the phone on Tuesday.