VANCOUVER — In November last year, American border agents ordered that a freight train crossing into the U.S. be halted.

Homeland Security agent David Spitzer said in an affidavit that 13 Mexican nationals were discovered and many “attempted to abscond after the train was ordered to stop.”

But the scene didn’t take place on the U.S. border with Mexico — it unfolded just south of Vancouver, where American prosecutors and law enforcement officers say they’re dealing with a huge increase in human smuggling from British Columbia.