By DEBORAH RAMIREZ
Of The STAR Staff

The Sunday attack on the Federal Building in Hato Rey which shattered seven windows marks the first time a U.S. Army weapon has been used in a terrorist attack on the island, an FBI spokesman said Monday.

The bazooka-like weapon, designed to penetrate the hull of a military tank and explode inside it, was mass-produced by the Army during the 1960s and first used in the Vietnam War. The weapon is pre-assembled and can be fired only once.

The approximately 4-foot-long device, containing three pounds of dynamite and with a range of about 350 meters, is called a Light Anti-Tank Weapon (LAW) and was identified by Roosevelt Roads Navy Base personnel, according to FBI special agent Diader H. Rosario.

Answering questions during a news conference at FBI headquarters at the Chardón Street building Monday, Rosario said that the LAW device may have been stolen by someone with access to an Army base.

"This weapon was created by the North American armed forces and one would think it would be used only for military purposes. But that doesn't rule out that it could fall into terrorist hands," he said.

Another FBI official added that a person operating the device would probably need some military training or a military manual. "Otherwise, he would be guessing," the official said.

Rosario said the highly explosive projectile hit a concrete column in the back of the building, on O'Neill Street and which faces Roosevelt Avenue.

The agent speculated that the military weapon was probably fired from Roosevelt Avenue or a nearby street. FBI agents who were in the office at 7:43 p.m. when the incident occurred, heard a loud explosion and saw fragments of metal sputtering through the air, Rosario said.

For security reasons, he refused to say how many agents were working at the time.

The shot hit the column slightly below the sixth floor and about 10 feet above the FBI's fifth floor offices. Although FBI officials offered no damage estimate, the shot shattered four windows of the U.S. Agriculture Department on the sixth floor, and three FBI office windows.

The concrete column also suffered structural damage.

A woman called Associated Press Sunday night claiming that a terrorist group known as Los Macheteros launched the attack in retaliation for the U.S. military invasion of Grenada.

In the past, the group also has claimed responsibility for the Sabana Seca attack on U.S. Navy personnel which left two sailors dead in 1979; the bombing of the Muñiz Air Base which destroyed nine Air National Guard fighter jets in 1981; and the fatal shooting of one U.S. sailor and the wounding of three others in Puerta de Tierra in 1982.

On Monday, a woman called United Press International saying that a press release prepared by the terrorist group could be found on the grounds of El Morro in Old San Juan.

The press statement described the attack as an act of "fraternal solidarity with the heroic people of Grenada."