SAN JUAN, JUNE 18 -- Five former police officers were sentenced today to prison terms of up to 30 years for the 1978 murders of two advocates of Puerto Rican independence from the United States.

The killings caused a political uproar and led to a legislative investigation that found that the two were slain after they had surrendered.

The five former lawmen pleaded guilty in commonwealth court earlier this month to reduced charges of second-degree murder and perjury. A sixth, William Colon Berrios, pleaded guilty to conspiracy and perjury and is to be sentenced Aug. 26.

Eight police officers were charged with murder in the deaths of Carlos Soto Arrivi, 18, and Arnaldo Rosado, 24, at Cerro Maravilla mountain in the island's center.

Trial for the remaining two defendants is set for Aug. 31.

Jaime Quiles, Nelson Gonzalez Perez, Rafael Torres Marrero and Nazario Mateo Espada were sentenced to up to 30 years for each count of second-degree murder and six years for each perjury count. Juan Bruno Gonzalez was sentenced to up to 13 years for each murder count, plus six years for each count of perjury.

Soto Arrivi and Rosado were killed when police staked out a television relay tower that they allegedly planned to sabotage.

The story given by police at the scene -- that the two allegedly opened fire at the officers -- was disputed by the island senate's probe, which indicated police set up the operation and shot the two from close range after they surrendered.