Roberto D'Aubuisson, the charismatic leader of the Salvadoran right and alleged mastermind of the 1980s death squads, died Thursday at age 48, his doctor said.
Dr. Jose Luis Saca said Mr. D'Aubuisson, who had been battling throat cancer since April, died of heart failure at 4:45 p.m. in the intensive care unit of the downtown Hospital Diagnostico.
President Alfredo Cristiani, a member of Mr. D'Aubuisson's party, declared three days of mourning.
San Salvador Mayor Armando Calderon Sol, president of the Republican National Alliance that Mr. D'Aubuisson founded, called him "a great patriot" and hailed him as "a constructor of Salvadoran democracy and peace."
Mr. D'Aubuisson's gregarious machismo and ruthless determination made him El Salvador's most charismatic political leader of modern times.
Mr. D'Aubuisson was an army intelligence major when reform-minded officers staged a coup in 1979 in an unsuccessful effort to head off civil war.
He founded the Republican Nationalist Alliance, or Arena.
Many diplomats and non-rightist politicians considered the Arena of those days little more than a political front for the paramilitary forces blamed for murdering thousands of suspected leftists.
Former U.S. Ambassador to El Salvador Robert White described Mr. D'Aubuisson in the early 1980s as "a pathological killer," and many Salvadorans agreed.
Jose Napoleon Duarte, who narrowly defeated D'Aubuisson in 1984 presidential race, accused him of ordering the 1980 assassination of Monsignor Oscar Romero.