The Police Tactical Unit (PTU; Chinese: 警察機動部隊) is a unit within the Hong Kong Police Force which provides an immediate manpower reserve for use in large-scale emergencies. Unit companies are attached to all land Regions and are available for internal security, crowd control, anti-crime operations, disaster response and riot control throughout Hong Kong. The PTU is the parent unit for the Special Tactical Contingent (STC), which specializes in riot control drawing members from other units including the PTU Headquarters and the Special Duties Unit (SDU) for temporary ad hoc tasks.