A wave of attempted bombings spread up the East Coast yesterday from New York City, where a pipe bomb was removed from the United Nations garage, to a Connecticut store and a crowded Boston bus terminal. All of the explosives were removed safely.

The pipe bomb found on a sanitation truck in the U.N. garage was the sixth bomb planted in New York City in the last six days.

A Puerto Rican group has claimed responsibility for three of the bombs, including one that exploded Saturday at Kennedy Airport and killed a 19-year-old news vendor.

No other injuries have resulted from the bombs but diplomats and executives have been scrambling for bomb detection equipment, bulletproof vests and even armored cars.

Police said they did not believe the same people were resonsible for the bomb found at the United Nations an hour after an anonymous caller on the police department's 911 emergency line" said something about injustice" and warned that six bombs were planted in the U.N. basement.

Anonymous callers also led police to a hand grenade at the Trailways bus terminal in Boston and two bombs outside a Hamden, Conn., department store. In each case, the callers gave no reason for the bombs, and no one claimed responsibility.

In New York, police have received more than 600 reports of suspicious packages and bomb threats since Saturday.