They were returning from Pakistan on the Samjhauta Express, said the report.
According to officials, the people arrested belong to Muzaffarnagar in Uttar Pradesh and had been visiting relatives in Pakistan. The arms were concealed under meat grinders, which were cut open with gas cutters at the railway station.
The people arrested belong to Muzaffarnagar and were returning from Pakistan
Attari is a small town three km from the Pakistan border and about 25 km away from Amritsar.
There was intelligence report that some people from Muzaffarnagar, which was the epicentre of riots in September last year, could be used as couriers to smuggle in arms.
The six people were detained on Thursday afternoon and were interrogated by the Intelligence Bureau officials.
All the six people arrested got off the Samjhauta Express that runs twice a week between Delhi and Lahore in Pakistan.
Muzaffarnagar witnesses communal riots in September last year. Over 60 people were killed in the violence which lasted over three weeks. Thousands were left homeless.
Last year, Congress vice president Rahul Gandhi, in a rally, had said that terror agents from Pakistan had approached Muzaffarnagar riot victims. His statement had created huge furore in the country and the election commission had sought an explanation from him.