By 1965 , the PKI extensively penetrated all levels of government and gained influence at the expense of the army . On 30 September 1965 , six of the military 's most senior officers were killed in an action ( generally labelled an " attempted coup " ) by the so-called 30 September Movement , a group from within the armed forces . Within a few hours , Major General Suharto mobilised forces under his command and took control of Jakarta . Anti-communists , initially following the army 's lead , went on a violent purge of communists throughout the country , killing an estimated half million people and destroying the PKI , which was officially blamed for the crisis
a violent purge of communists throughout the country
Indonesian mass killings of 1965–66
Politics of Indonesia