What's this with 10 dead in the US?
Between 1974 and 1983, the Armed Forces of National Liberation of Puerto Rico, of Marxist-Leninist ideology, perpetrated 120 attacks in which 6 people were killed.
Between 1975 and 1984, the United Freedom Front (UFF), a small criminal organization with Marxist ideology, perpetrated a score of attacks, killing one person.
Between 1978 and 1985, the May 19th Communist Organization perpetrated various attacks and robberies, killing 3 people.