A 12-year-old boy was robbed at gunpoint less than a block away from an elementary school on Chicago’s South Side Monday, according to police.

Police said a man robbed the boy around 8 a.m. in the 8200 block of South Rhodes Avenue. The man displayed a weapon before taking an undisclosed number of items and fleeing the scene, Chicago Police News Affairs said.

The robbery took place roughly one block from Dixon Elementary School, located at 8306 S. St. Lawrence Ave.

In a letter to parents Monday, Dixon Elementary School’s Principal, Sharon Dale, said multiple students were “accosted” as they walked to school.

“It is imperative to tell your children to go directly home, do not stop, at the candy store or anywhere else, before or after school,” the letter read. “Walk with a friend and go directly home.”

One of the victims told NBCChicago the group of four boys was walking to school when a man came up to them and showed them a gun in his waistband. The man asked for the boys' phones, but only one boy had one to give.

The offender was described as a black man with dark complexion and tattoos on his face who was between the ages of 18 and 22 and stood between 5 feet, 10 inches to 6-feet tall.

The victim said the man was also wearing a Gucci belt, True Religion jeans, black boots and a dark Nike "Just Do It" jacket. Police could not confirm those details.

CPS declined to comment on the matter.