A caller claiming to represent a previously unknown terrorist group took responsibility for a shooting attack on four American sailors in which one was killed and the three others seriously injured.
The San Juan FBI office said a caller told a local radio station the ''Group for the Liberation of Vieques'' claimed responsibility for the attack. Vieques is an island off Puerto Rico which the Navy owns in part and uses as a target range. Leftists and terrorists have repeatedly denounced the practice. The FBI was not sure the call was authentic.