Dunkirk Police are warning city residents about a phone call scam involving National Grid. A resident recently received a phone call from a person claiming to be a National Grid collections agent. The person was advised that they owed National Grid money and needed to purchase a gift card for at least the amount owed. The person was then told to call the collections agent back, and the agent would use the information from the card to withdraw the owed amount over the phone from the card. Dunkirk Police say National Grid does not collect owed amounts in that manner. Officers are advising anybody who receives this call to ignore it and hang up.