UPDATE 6:40 A.M.: Police have cleared the scene and students are allowed to return to campus. There are reports of an overnight break-in and vending machine theft. Police have determined that the culprit is not in the school.
Police surround Cheyenne High School after possible break-in.
Police are urging teacher and students to stay out of the building while they search the premises with canines.
No other details are currently available.