Milicja Obywatelska

Milicja Obywatelska (), in English known as the Citizens' Militia and commonly abbreviated to MO, was the national police organization of the Polish People's Republic. It was established on 7 October 1944 by the Polish Committee of National Liberation, effectively replacing the pre-war police force. The Citizen's Militia would remain the predominant means of policing in Poland until 10 May 1990, when it was transformed back into "Policja".
The term "milicja" had been adapted from the cognate term, "militsiya", used in several communist countries. The term is derived from "militia", which derives its etymology from the concept of a military force composed of ordinary citizens. In most cases it represented a state-controlled force used to exert political repression, especially with its elite ZOMO squads.
Under both communist and post-communist governments, the Polish police system has traditionally operated under the auspices of national authority. Starting at the end of World War II, Poland went under the influence of the Soviet Union. In 1948, the country's turn toward Stalinism brought the beginning of totalitarian rule, "in which one Party ruled autonomously over all sections of society". Training for the force was conducted in the town of Legionowo. 
Organisation.
The Citizens' Militia was divided into a Public Order Department, Traffic Militia (Highway patrol), Criminal Investigations (Major crimes, forensics), Investigations Militia and an Infrastructure Security Section (Security of government buildings, airports, installations).
There were regional, district, city and local detachments of the force.
The ZOMO motorized riot troops, which played the most visible role in quelling demonstrations in 1980 and 1981, were reduced in size somewhat by the early 1990s and renamed Preventive Units of the Citizens' Militia (—OPMO). OPMO forces are restricted to roles such as crowd control at sporting events, ensuring safety in natural disasters, and assisting the regular police. In theory, higher government authority would be required for large OPMO contingents to be used.
From the 1960s through the 1980s, ORMO forces, which at one time numbered as many as 600,000 civilian volunteers, were used to augment regular police personnel at key trouble spots. In the early 1980s, ORMO harassed Solidarity members and prevented independent groups from organizing. Largely staffed by industrial workers who gained substantial privileges by monitoring their peers in the workplace, ORMO was the object of extreme resentment throughout the 1980s. Kiszczak attempted to promote ORMO as a valuable auxiliary police force, but the organization was abolished by the Sejm in 1990.
Transportation.
The most common types were: