POLICE made four arrests at Harrow and Wealdstone Station after immigration officials stopped and checked the identities of passers-by.
Three people were detained for immigration offences and the fourth for immigration offences and also on suspicion of carrying a forged ID card.
Wednesday's multi-agency operation outside the station in The Bridge, Wealdstone, involved the UK Border Agency and Harrow Police's Headstone North Safer Neighbourhood Team.
The team had organised the routine crackdown as part of Operation Blunt 2, a London-wide campaign on knives and blades.
Officers questioned passengers and pedestrians and asked them to walk through a metal detector, known as a knife arch, as well as checking their validity of their identity papers.
There were no knife-related arrests.