The weapons were concealed in the base of meat grinders, which were cut open with gas cutters.
Six people, including two women, were arrested at the Attari railway station in Punjab on Thursday while they were returning from Pakistan on the Samjhauta Express. Eleven pistols and 20 magazines were seized from them, customs officials said.
They also added that all those arrested belong to Muzaffarnagar in Uttar Pradesh and had been visiting relatives in Pakistan. The weapons were concealed in the base of meat grinders, which were cut open with gas cutters at the railway station.
Sources said there was intelligence 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 at about 1.30 on Thursday afternoon as they alighted from the Samjhauta Express, a train that runs twice a week between India and Lahore in Pakistan. They were interrogated till late in the night by officials of the Intelligence Bureau.
All those arrested are currently in custody of intelligence officials. They will be produced before a magistrate in a court in Amritsar later today.
Attari is a small town three km from the Pakistan border and about 25 km away from Amritsar.
Officials said all six were to have traveled by bus to Delhi and then back to UP, where they were to have allegedly delivered the weapons.
In September last year, riots tore through Muzaffarnagar district. Over 60 people were killed in the communal violence over three weeks and thousands were left homeless and in distress through a bitterly cold winter.