NEW YORK (CBSNewYork) — Police are looking for a man who they say poses as a cop before robbing livery cab drivers in Queens.

The man struck seven times in eight days this month, stealing cellphones, credit cards and nearly $1,000 in cash, police said. The first robbery occurred Feb. 2, while the most recent theft happened Monday, cops said.

Livery cab drivers picked up the suspect at or near John F. Kennedy Airport, authorities said. He then claimed to be a police officer and displayed a firearm, though not a badge, and demanded valuables, police said.

He fled the cars at different locations in Springfield Gardens and Jamaica, Queens, police said. The crimes typically occurred at night or early in the morning.

Police initially said the suspect was picked up at the airport before all of the robberies, but the Port Authority later said only one of the crimes originated at JFK.

Police have released surveillance video, photos and a sketch of the suspect. He is described as a black man, about 5 feet 10 inches tall and 160 pounds.

A sketch of a man who police say poses as a cop before robbing livery cab drivers in Queens. (credit: NYPD)

A sketch of a man who police say poses as a cop before robbing livery cab drivers in Queens. (credit: NYPD)

Douglas Williams, an Uber driver, said he doesn’t carry cash since all the company’s passengers pay by credit card.

Still, he’s on alert.

“Nothing you can do but just be aware,” he told CBS2’s Andrea Grymes. “Watch people who are approaching you. I keep an eye on all four mirrors constantly.”

Anyone with information about the robberies is asked to call Crime Stoppers at 800-577-TIPS, visit www.NYPDCrimeStoppers.com or text tips to 274637 (CRIMES) then enter TIP577.