The Airport Security Unit (ASU; Chinese: 機場特警組) is the airport police of the Hong Kong Police Force tasked with the security of the Hong Kong International Airport. The ASU was originally formed in 1977 as the Special Action Squad on standby for security at Kai Tak Airport and in 1978 following a review it was renamed as the Airport Security Unit and commenced patrolling the airport. In 1998, the ASU moved to the Chek Lap Kok Airport.