Police cordoned off part of Collyer Avenue after a group of boys were found to be 'causing a disturbance' at The Regis School at about 3.30pm.
A group of boys left just as officers arrived but were later found to be on the roof of some garages nearby.
A spokesman for Sussex Police said: "Our officers have cordoned off a small part of Collyer Avenue in Bognor following a report of youths causing a disturbance at The Regis School nearby on Thursday, January 13.
"Police were called at 3.30pm over reports of the disturbance, and a group of boys left the area when officers arrived.
"They were then located on a single storey garage roof above a property at Collyer Avenue nearby, and officers are engaging with them in order to bring them down safely.
"A small road closure is in place in Collyer Avenue, and officers have thanked residents for their patience while the incident is resolved."