Security employees of a prison contractor approved by the General Assembly to operate a prison facility pursuant to § 53.1-265 shall be allowed to use force and shall exercise their powers and authority only while on the grounds of an institution under the supervision of the prison contractor, while transporting inmates, while pursuing escapees from such institutions, and while providing inmate security for prisoners at a medical facility in the Commonwealth. All provisions of law pertaining to custodians of inmates, correctional officers, or prison or jail officers, except § 19.2-81.1, shall apply to contractors’ security employees.