Commuters on the Long Island Railroad who use ticket vending machines should check their accounts for unauthorized withdrawals.
MTA police say thieves are trying to steal credit and debit card information.
They recently found card skimming devices and tiny hidden cameras on vending machines at the LIRR station in Baldwin.
Four people were arrested in November for skimming credit and debit card information from LIRR commuters.
Police say the suspects struck at six to eight stations on Long Island and the Bayside station in Queens.
Authorities first became aware of the skimming scheme when one MTA customer found a small video camera on the floor at one of the train stations. That prompted MTA police to start checking hundreds of other machines at other LIRR stations.
They found a small hidden camera on the underside of a black metal strip planted across the top of each ticket machine with an adhesive. The black metal strips blended in perfectly and looked like they were in fact part of the machine.