Irish Rail says it is concerned about the theft of luggage and bags from passengers on the Sligo/Dublin line.
It also says it is working with the gardai to apprehend those responsible.
It follows the recent theft of bags from at least four passengers travelling on trains on the line.
One woman spoke of an ipad having been taken from her bag.
Irish Rail spokesperson Jane Creegan says that despite the latest thefts, such incidents are isolated overall.
