The territory has nevertheless maintained a Government Flying Service, formerly the Royal Hong Kong Auxiliary Air Force, that is responsible for search and rescue operations, air ambulance services, and other air services for the Hong Kong Government. The GFS also took over some responsibilities from the Royal Air Force and the Army Air Corps. The Hong Kong Police Force also has a highly trained and equipped counter terrorism unit, the Special Duties Unit, trained by United Kingdom's SAS and SBS, and a Marine Police force. These forces have been heavily armed since before the handover in 1997, and are within the portfolio of the Secretary for Security (which, before 1973, was named Secretary for Defence).