Marching troops salute their leaders at the May Day celebrations in Sofia,Bulgaria

May Day celebrations in the "9th of September Square" in Sofia, Bulgaria. Marching troops of workers, men and women, and troops of children through the streets of the capital. The marching troops carry with them the posters of their leaders, including the late Georgi Dimitrov. They cheer and express their respect for the Soviet Union. Members of the Government and political leaders, including Vulko Chervenkov, are saluted by the marching people and troops.