The incident happened in coach C – 13 on Train No. 20702 after passing Gudur, said the official. "An unauthorised passenger boarded the train from Tirupati and locked himself in the toilet of C-13 coach... The passenger smoked inside the toilet which resulted in automatic activation of aerosol fire extinguisher present inside the toilet," an official from South Central Railway (SCR) Zone's Vijayawada Division said in a press release.

Following the false alarm, the aerosol fire extinguisher started emitting powder-like smoke to douse the flame and in that process, the passengers in that coach panicked. Later, they relayed the information to the train's guard through an emergency phone connection inside the coach, leading to the train getting halted at Manubolu around 5 pm.

Mistaking the false alarm to be a fire accident, the Railway police rushed to the coach with a fire extinguisher and broke the toilet's window to save the passenger who was smoking inside it.?Railway police detained him at Nellore for appropriate action as per the Railway Act, the official added while the train resumed its journey later.