SAN JUAN, Puerto Rico (AP) -- A Puerto Rican independence activist convicted of trying to bomb a McDonald's restaurant in the 1970s was arrested Monday on charges that he sold a bomb to drug smugglers.

Local police and federal agents arrested Guillermo Segarra Rivera, 45, at his home in Patillas, in southern Puerto Rico.

Segarra Rivera was caught in 1975 planting a bomb at a McDonald's in San Juan as part of a police sting operation. Police defused the bomb, and Segarra was sentenced to five years in jail.

However, he was paroled by 1978, when police charged him with planting a bomb in front of a U.S. post office in suburban San Juan and with buying a shotgun later used in an attack on a guardhouse near the home of former Gov. Luis Munoz Marin.

Segarra Rivera was acquitted of the charges. Police claimed he had a guerrilla group called the Anti-Imperialist Armed Forces, but Segarra Rivera and other activists said the police made up the name and that the group never existed.

The undercover agent who aided in his arrest, Alejandro Gonzalez Malave, was later linked to the police ambush and killing of two independence activists on the mountain of Cerro Maravilla.

That killing galvanized the Puerto Rican independence movement in the late 1970s and early 1980s.