The girl and her brother, hailing from neighbouring Lakhimpur district, arrived at the railway station from Guwahati in Kamakhya Express late on Thursday night and as they went to separate rest rooms there, the group of jawans from 58 Engineers Regiment allegedly molested the girl, police said.
They first locked the brother's rest room door and then entered the girl's rest room and sexually assaulted her, the police said.
As she screamed for help, nearby people came to her rescue and thrashed the jawans and handed four of them to police. One of them fled away.
Today the fifth jawan Kamal Bahadur Chetri who had fled was handed over by the army authorities to the police station, the police said.
All the five were produced in court which sent them to judicial custody.