 In one incident, RCMP officers clashed with striking coal miners for 45 minutes in Estevan, Saskatchewan in 1933 and killed three miners during the Estevan Riot.Part of its strategy against labour organizing included extensive use of spies for surveillance of suspected Communists, which was revealed at the court trial that convicted the leadership of the Communist Party under Section 98 of the Criminal Code in 1932.Political surveillance activities were conducted out of its Criminal Investigation Department until a separate branch, the RCMP Security Service, was established in 1950.