A Patchogue teenager stabbed a security guard at the “Live at Five” festival during an altercation on Friday night, Suffolk police said.

Witnesses reported that Dylan Bryan, 17, shoved and fought with security guards, who were hired by the village of Patchogue to check IDs for age, maintain order and discourage open alcoholic beverages on Main Street shortly after 9 p.m., according to 5th Squad detectives. Bryan was stopped at a checkpoint where he stabbed Robert Martinez, 38, of Port Jefferson Station, an employee of PSA Security, in the leg, police said. Bryan was then subdued by several security personnel, who held him until police arrived.

Martinez was treated at Brookhaven Memorial Hospital and released. Bryan, who also suffered an injury to his upper leg, was treated at Stony Brook University Medical Center. He was charged with second-degree assault and possession of a weapon. He will be arraigned at First District Court in Central Islip, at a later date.