rapid response unit; emergency squad
Refers to a specialized team deployed quickly for emergencies, such as police SWAT, military rapid-reaction forces, or disaster response units.
The rapid response unit rushed to the scene.
The police emergency squad headed out to rescue the hostages.
特殊部隊 refers to special forces in a broader military sense, often with advanced training for unconventional warfare, while 緊急部隊 emphasizes rapid deployment for urgent situations.
機動隊 is the Japanese riot police unit, primarily for public order and crowd control, whereas 緊急部隊 is a more generic term for any emergency response team.
Compound of 緊急 (emergency, urgent) and 部隊 (unit, corps). A straightforward modern formation.