Detectives are looking for a man who they said robbed the open-air post office in downtown St. Petersburg.

According to the St. Petersburg Police Department, the suspect walked into the post office, located at 76 Fourth Street N, at about 4:15 p.m. on Monday and asked for a book of stamps.

After the clerk rang up the sale, the suspect slid a newspaper across the counter with a note written on it, indicating that he was robbing the post office, police said. The suspect then said he was armed, although no gun was ever seen.

Police said that the clerk gave him money, and then the suspect ran from the post office.

The suspect is described as a black man in his late 30s or early 40s, who stands six feet tall and weighs about 190 pounds. He was last seen wearing a black and purple ball cap, large dark sunglasses, black sweat pants and a black sleeveless shirt.

Anyone with information about the suspect is asked to call police at 727-893-7780.