CCTV images have been issued by police investigating thefts on trains and at railway stations.
Officers believe those captured on the stills could hold vital information about offences committed across the county.
The pictures have been released on the day British Transport Police launched Operation Impact - a new crackdown on thefts of suitcases, bags, mobile phones and laptops onboard trains and at stations.
Operation Impact will involve both covert and overt policing and will see dedicated teams of officers travelling on trains and increasing patrols to target crime hotspots.
Officers will be issuing crime prevention advice to rail passengers.
Chief Inspector Glen Alderson said: “We’re asking for help from members of the public. If you know any of these people and can tell us who they are, we want to hear from you.
“We know that a large majority of items are stolen after they have been left unattended, so I would urge passengers to stay alert and keep their luggage close by and in view at all times if possible, and check on it regularly throughout their journey.
“We will continue to work closely with Network Rail and train operating companies to tackle theft. Please report any suspicious behaviour to a member of staff or police.”
n Anyone with any information should call British Transport Police on 0800 405040 or text BTP’s non-emergency line on 61016.