In a public appeal, the army said Captain Shikhar Deep, posted in Jammu and Kashmir with the 8 Sikh Light Infantry regiment, was travelling by Mahananda Express (15483) from Katihar to Delhi on February 6-7.
"The officer did not reach his destination and went missing during transit. Any information with regard to the whereabouts of the officer may please be conveyed to Lt Col Anant Kumar on mobile number 9128724351," it said.
The 25-year-old officer's relatives had registered a case of suspected abduction with the railway police on Tuesday.
His father, Lt Col Anant Kumar, who is posted in Ranchi, has claimed Sikhardeep's disappearance could be linked to some terrorist organisation.
According to the police, while his luggage was found intact in the train coach he was travelling in, the officer was nowhere to be found and his mobile was also switched off.
The ticket examiner and the man, who provided bedsheet in the coach, said he was last seen at Kanpur during the journey.
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