The Presidency of Juan Bosch in 1963 led to one of the tensest periods in contemporary Haitian-Dominican relations. Bosch supported the efforts of Haitian exiles who trained to overthrow François Duvalier, Haiti's repressive president. In April 1963, former Haitian army officers reportedly tried to kill Duvalier's children, and many of those accused took refuge in the embassies of Latin American countries in Port-au-Prince, the Haitian capital. When Haitian police raided the Dominican embassy and held captive 22 refugees, the Dominican Republic broke off diplomatic relations and threatened to invade Haiti. The OAS mediated the dispute and eased the tension; Dominican troops, ready to invade, pulled back from the border; and many of the refugees were granted safe conduct out of Haiti. Hostilities erupted again in September that year when both sides shelled each other across the border. The OAS again intervened to make peace.