Other victims of Condor included, among hundreds of less famous persons, Juan José Torres, the former President of Bolivia, assassinated in Buenos Aires on 2 June 1976; Carmelo Soria, a UN diplomat working for the CEPAL, assassinated in July 1976; and Orlando Letelier, a former Chilean ambassador to the United States and minister in Allende's cabinet, assassinated after his release from internment and exile in Washington, D.C. by a car bomb on 21 September 1976. This led to strained relations with the US and to the extradition of Michael Townley, a US citizen who worked for the DINA and had organized Letelier's assassination. Other targeted victims, who escaped assassination, included Christian-Democrat politician Bernardo Leighton, who barely escaped an assassination attempt in Rome in 1975 by the Italian neo-fascist terrorist Stefano delle Chiaie (the assassination attempt seriously injured Leighton and his wife, Anita Fresno, leaving her permanently disabled); Carlos Altamirano, the leader of the Chilean Socialist Party, targeted for murder in 1975 by Pinochet, along with Volodia Teitelboim, writer and member of the Communist Party; Pascal Allende, the nephew of Salvador Allende and president of the MIR, who escaped an assassination attempt in Costa Rica in March 1976; and US Congressman Edward Koch, who became aware in 2001 of the relationship between death threats he received and his denunciation of Operation Condor. Furthermore, according to current investigations, Eduardo Frei Montalva, the Christian Democrat President of Chile from 1964 to 1970, may have been poisoned in 1982 by a toxin produced by DINA biochemist Eugenio Berrios. Berríos himself is reputed to having been assassinated by Chilean intelligence in Uruguay, after being spirited away to said country in the early 1990s.