security police

noun
  1. a police force responsible for maintaining order at a specific locale or under specific circumstances, as at an airport or factory.
  2. a police force concerned with detecting and preventing enemy espionage.
  3. secret police.

Origin of security police

First recorded in 1915–20
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018