US terror net exposed, FBI says

A terrorist conspiracy involving the main US leftist underground groups - and possibly European militants like the Irish Republican Army - has been uncovered in the wake of two New York shootouts last week between police and guerrillas, FBI officials report.

A dragnet through New York and New Jersey turned up a startling string of ''safehouses'' stocked with weapons, disguises, and plans for possible future bombings - supporting evidence of an apparent union of the long dormant Weather Underground and the Black Liberation Army.

The radical underground - a hunted but seldom touched enclave of fugitives from the days of the antiwar demonstrations - was cracked wide open as the FBI swooped in after an abortive guerrilla raid on an armored car carrying $1.6 million. Two policemen and a guard were killed in that suburban New York shootout Tuesday. And on Friday, a gunman was killed and a second captured in a high-speed chase and shootout in Queens after police linked their car to the Rockland robbery.

The first incident sparked a nationwide manhunt for ''extremely dangerous'' fugitives connected with the conspiracy. It also prompted the FBI raids, which have offered firm evidence of a ''terrorist infrastructure,'' said Kenneth Walton, head of the FBI's New York office. The radical alliance is believed to include the Weather Underground, the Black Liberation Army, the May 19 group, and the Puerto Rican FALN.

Although unsure of what the ultimate aims of the groups were, he speculated that the Weather Underground's aim was the same as it was in the 1960s, when the group grew out of the anti-Vietnam War protests: to undermine society.