The incident happened at 7-Eleven, located at 148 Pine Aire Drive in North Bay Shore, at about 10:20 p.m. on Saturday, Jan. 15, according to Suffolk County Crime Stoppers.
Authorities said the two men approached another man and ripped a gold chain off his neck.
The men drove away from the scene in a Hyundai SUV, authorities reported.
Crime Stoppers is offering a cash reward for information that leads to an arrest.
Tips can be submitted by calling 1-800-220-TIPS.
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