Customs officials said the heroin was seized from 68 DN goods train that arrived at the Attari railway station.
During rummaging, customs officials detected two packets concealed in upper cavities in two wagons of the train.
When the packets were opened an off-white colour powder weighing approximately 1 kg was seized, officials said.
A case has been resgistered under the provisions of the Customs Act, 1962 and the NDPS Act, said Commissioner Custom Amritsar Captain Sanjay Gahlot.