>"Apart from Islamic fundamantalist terrorist organisations, what other terrorist group or groups refer to any of their attacks as "martyrdom operations"?"

The murder of George Tiller for one by members of Operation Rescue.
Also, Tim McVeigh. The idea that this must be Islamic is a tinfoil hat idea.

The newspapereze label of "martyrdom operation" is a term immediately to be distrusted
as identifying anything of importance.

There are many Xtian terrorist paramilitary and skinhead groups in the U.S. that would use the term "martydom" for their cause.