Grammar usage

I concur with Tolley: I have never heard of either verb used with off.  However, I found references online to both verbs being phrasal, paired with off:

trigger: (usually foll by off) to give rise (to); set off [http://www.thefreedictionary.com/trigger]

spark off: (tr, adverb) to bring into being or action; activate or initiate to spark off an argument
  [http://www.thefreedictionary.com/spark+off]

I would tend to agree with Tolley that these phrasal verbs are so uncommon as to probably be regional. 

To give you an example (which reveals my political leanings, and my cynicism) I would suggest that in the following sentence, the main verbs trigger or spark are much, much more common than the phrasal verbs referenced above:

The American House of Representatives' vote to reject Obama's proposed ban on semiautomatic weapons triggered/sparked a riot by gun control advocates in the nation's capital.