A crook asked a man for a cigarette before robbing him of a cell phone in the Tenderloin neighborhood Sunday, police said.

The suspect backed the victim into a wall and threatened to shoot him in the 400 block of O’Farrell Street around 6:45 a.m., police said.

The victim, a man in his 20s, did not see the gun, saying only that the suspect acted as if one was hidden in his sweatshirt pocket, police said.

The suspect reached into the victim’s pocket and grabbed the cell phone. Nothing else was taken during the robbery, police said.

There has been no arrest.

maldax@sfexaminer.com

Follow The San Francisco Examiner’s crime blog, Law & Disorder, on Twitter @sflawdisorder.