Sirimavo Bandaranaike , the widow of Bandaranaike , took office as prime minister in 1960 , and withstood an attempted coup d'état in 1962 . During her second term as prime minister , the government instituted socialist economic policies , strengthening ties with the Soviet Union and China , while promoting a policy of non-alignment . In 1971 , Ceylon experienced a Marxist insurrection , which was quickly suppressed . In 1972 , the country became a republic named Sri Lanka , repudiating its dominion status . Prolonged minority grievances and the use of communal emotionalism as an election campaign weapon by both Sinhalese and Tamil leaders abetted a fledgling Tamil militancy in the north during the 1970s . The policy of standardisation by the Sirimavo government to rectify disparities created in university enrolment , which was in essence an affirmative action to assist geographically disadvantaged students to obtain tertiary education , resulted in reducing the proportion of Tamil students at university level and acted as the immediate catalyst for the rise of militancy . The assassination of Jaffna Mayor Alfred Duraiyappah in 1975 by the Liberation Tigers of Tamil Eelam ( LTTE ) marked a crisis point . The government of J. R. Jayawardene swept to power in 1977 , defeating the largely unpopular United Front government . Jayawardene introduced a new constitution , together with a free-market economy and a powerful executive presidency modelled after that of France . It made Sri Lanka the first South Asian country to liberalise its economy . Beginning in 1983 , ethnic tensions were manifested in an on-and-off insurgency against the government by the LTTE . An LTTE attack on 13 soldiers resulted in the anti-Tamil race riots in July 1983 , allegedly backed by Sinhalese hard-line ministers , which resulted in more than 150,000 Tamil civilians fleeing the island , seeking asylum in other countries
race riots
Black July
Sri Lanka