From the truth is stranger than fiction department, an article by Jim Henley (not Hanley) in the online American Spectator identifies the first use in fiction of suicide bombers -- Avengers #113, written by Steve Engelhart in 1973. This was some seven years before the Tamil Tigers first used suicide bombers as a terrorist tactic.
In the story, a small group of bigots opposed to the romance of the Scarlet Witch and the Vision (because he's an android) strap explosives to themselves and attempt to get close to their targets. The Living Bombs also refer to themselves as 'martyrs.'