Members of an underground pro-independence group penetrated the Muniz Air National Guard base near San Juan early today, destroying eight A7 Corsair and F104 Starfighter jets and damaging two other aircraft.
Government officials estimated the damage at $45 million.
The attackers placed bombs in 13 aircaft, either in the air intake ducts or the wheel wells. Bombs that exploded in the wheel wells ignited fuel in the tanks and demolished those planes. The bombs that exploded in the air intakes did limited damage.
An old F104 -- on display at the head of a row of aircraft -- was broken into two large sections. Three other planes escaped damage when the pipe bombs found planted on them failed to explode. Six other planes, including several in a hangar, were untouched by the terrorists.
Two watchmen, both Air Guard civilian employes, were on duty when the bombs exploded about 1:30 a.m. Neither was injured.
An anonymous telephone caller told the Associated Press today that a Marxist-Leninist group called the Macheteros made the attack. Macheteros first surfaced in 1978, in connection with the ambush slaying of a policeman. In December 1979, they supposedly took part in the ambush of a Navy bus carrying personnel. Two Navy enlisted men died in that attack.
Residents of the area near the base called today for the shift of the Air Guard from the heavily populated area to the huge Roosevelt Roads Naval Base, located 35 miles east of San Juan, or to Ramey Field, a former Stategic Air Command base located 100 miles west of the city.
Both facilities are regarded by the military as much better from an operational standpoint than Muniz, which is situated near the end of the main runway at San Juan International Airport, where the sky is cluttered with heavy passenger and cargo traffic.
In 1971, preliminary work began on the proposed transfer of the Air Guard to Ramey Field. That move had the backing of then-Gov. Luis A. Ferre, who doubles as Republican state committee chairman for Puerto Rico. President Nixon and Defense Secretary Melvin Laird were sympathetic to Ferre's plea. But in 1972 Ferre lost his bid for reelection to Rafael Hernandez Colon, who had promised the union representing civilian employes at the Muniz base to oppoe transfer of the Air Guard out of San Juan.
Air Guard officials defending the use of a San Juan base contend they will be skilled technicians if the Guard shifts to one of the military bases relatively remote from the island's capital.
The devastating attack on the Air Guard planes, however, seems to have raised fresh doubt about the future of the small Muniz base, which has an easily scaled or pierced eight-foot fence. A Guard spokesman said the terrorists may have gained access through a freshly punched hole discovered in the fence.
Meanwhile the raiders' strike against the Air Guard base has sharpened disquiet in Puerto Rico over the island's political situation. The anonymous caller told the Associated Press that the action was a protest against a military draft, but the assault's date suggested possible other motives.
Jan. 12 is the anniversary of the birth of Eugenio Maria de Hostos, a 19th century patriot active in the struggle for independence from Spain. His anniversary is regularly marked by pro-independence protests against U.S. rule in Puerto Rico.
Destruction of the Air Guard planes also coincided with today's scheduled convening of the new legislative session. The two major political parties are locked in bitter controversy for control of the House of Representatives, with the outcome still to be decided by challenged votes.
San Juan Mayor Hernan Padilla, who took the oath of office for a second term this morning, called for an easing of political tension. After denouncing the attack on the Air Guard base, Padilla pleaded for peace before an island-wide television audience. CAPTION: Picture 1, Firefighters at Muniz Air National Guard base in Puerto Rico try to douse burning A7 Corsair fighter-bomber. Pro-independence terrorists destroyed or damaged 10 airplanes yesterday. Damage was put at $45 million. UPI; Picture 2, The nose and cockpit of an old F104 jet lie in front of the fuselage after bombing at air base in Puerto Rico. AP