In 1976–78, up to 500,000 were killed as a result of the Red Terror, a violent political repression campaign by the Derg against various opposition groups most notably the Marxist–Leninist Ethiopian People's Revolutionary Party (EPRP). The Red Terror was carried out in response to what the Derg termed the 'White Terror', a chain of violent events, assassinations, and killings carried out by what it called "petty bourgeois reactionaries" who desired a reversal of the 1974 revolution.