WASHINGTON - A Cuban exile long regarded as a violent opponent of Cuban President Fidel Castro has applied for asylum in the United States, a government official said Monday. Luis Posada Carriles, a suspect in the bombing of a Cuban passenger plane in 1976, reportedly slipped into South Florida several weeks ago but the Bush administration says it cannot confirm his whereabouts. Posada, a former senior officer of the Venezuelan intelligence service, denies involvement in the bombing, which killed 73 people, including 24 members of Cuba's national fencing team. To be eligible for political asylum, Posada must prove that he...