by Volko
One (1). Because it says "at any 1 destination, free Ambushes".Contrast this instruction with that of "Kill Zone": "FARC or AUC in a space executes 2 free Ambushes with any of its Guerrillas without Activating.". The Kill Zone event is the only time in the game that two Ambushes would occur on a single move.
Volko