BOSTON -- A Boston judge ordered a 17-year-old caught with a loaded gun inside Boston's English High School held on bail Friday, with the district attorney's office calling the case "chilling."

A West Roxbury District Court judge set bail at $100,000 for Walter West, Jr. of Dorchester, after he was charged with unlawful possession of a firearm, unlawful possession of ammunition, unlawfully carrying a loaded handgun, unlawfully carrying a firearm in a school, trespassing, and resisting arrest

"The defendant had a cocked and loaded 9 mm handgun inside a school," Conley said. “With rounds in the chamber and the magazine, it presented an extremely dangerous situation in a building full of innocents."

West and four other teens were arraigned in connection with the incident at English High Thursday after they entered the school and got into a fight with students there. None of the teens arrested attends the school.

Prosecutors said one of the teens, Damien Oliver, 17, let West, Tyrone Rutledge, 17 and two juvenile males, ages 13 and 16, into a side door of the building.

West was arrested after a struggle, police said, but the other teens fled and were apprehended later.

Officers said they seized a distinctive black, gray and red backpack that West had been wearing and found a Sturm, Ruger & Co. P95DC handgun with its hammer in the cocked position and rounds in its magazine and its chamber.

"This isn’t just a school case or a Boston case," Conley said. "A case like this should be chilling to every parent and every person in the Commonwealth who cares for children’s safety, no matter where those children live or go to school."

No students were injured in the incident and authorities did not indicate what prompted the disturbance.

West was scheduled to be back in court Dec. 8.