The 1973 Provincial Armed Constabulary revolt was a mutiny by Uttar Pradesh Provincial Armed Constabulary in May 1973 in demand of better pay, work conditions, etc. The army was called in to control the mutiny, which resulted in about 30 policemen shot dead and other hundreds arrested. It led to resignation of then congress ministry headed by Kamalapati Tripathi.
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1973 Provincial Armed Constabulary revolt Wikipedia(Text) CC BY-SA