A customer at a Valley Stream service station first asked for change of a $5 bill, then produced a handgun when the clerk looked down to open the cash register, police said.

“The subject then reached into the register, removed an undisclosed amount of money and fled the store,” Nassau County police said in a news release.

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There were no injuries in the robbery at 10:35 p.m. of the Exxon station at 206 N. Central Ave., police said.

The robber was described by police as being of average height and build, in his mid to late 20s, with “scruffy” facial hair and wearing a black knit hat, a black T-shirt with long sleeves, bluejeans and light-colored sneakers.