RIVERDALE - Police are searching for a man they say robbed at least seven New York City subway riders since January.

Authorities say the most recent robbery occurred on the 1 train at 238th Street in the Bronx. Police believe the suspect, who is a white man between the ages of 20 and 25, made off with cash and bank cards before fleeing the station. The victims say the man has approached them on the subway and displayed a knife or simulated a gun while demanding cash, cell phones and bank card pin numbers.

According to authorities, the victims have all been white men and women in their 20s and 30s. Officers describe the suspect as about 6 feet tall with a medium build and wearing a black cap with a black logo on the front.

Police ask anyone with information about the robberies to call Crime Stoppers at 1-800-577-TIPS.