Police in Brooklyn are searching for a group of teenage boys who have been robbing other boys of items they'd arranged to sell through Facebook. 

The pair of reported robberies happened inside the Cypress HIlls subway station at Jamaica and Autumn avenues, according to police. The first occurred at about 8:25 p.m. on Friday, Oct. 12, after the 16-year-old victim set up a meeting with the teens through Facebook chat to sell them his sneakers. The group forcibly took the victim's sneakers and fled. 

The second incident happened at about 6:40 p.m. on Sunday, Oct. 21, after the 12-year-old victim arranged through Facebook chat to meet with the group of teens, intending to sell his iPhone, police said. He was instead robbed by the teens. 

Police are searching for the four boys, about 16 to 20 years old. Anyone with information is asked to contact Crime Stoppers at 800-577-TIPS or at nypdcrimestoppers.com.