Around 72 suspected Bangladeshi nationals were offloaded from a train and detained in Assam's Nagaon district on Saturday, police said.
The passengers were travelling in the Rajyarani Express, which runs from Dhubri to Silghat in Nagaon district, and when the train stopped at Jakhalabanda station, the co-passengers reported the matter to police.
The border police was accordingly informed and the passengers taken into custody.
They have been asked to furnish documents to prove their nationality, police said.
Claiming to be daily wage labourers, the passengers said they were on their way to Silghat to find work at some construction site near the world-famed Kaziranga National Park.
Meanwhile, the All Assam Students' Union (AASU) and Asom Jatiyatabadi Yuba Chatra Parishad (AJYCP) stopped the train for more than three hours at Jakhalabanda station while it was on its way back to Dhubri in the evening demanding that railway authorities should stop such Bangladeshi nationals from boarding the train.