Sunni authorities suspect al Qaeda elements in Iraq provided guidance to alleged plotters . Iran has denied the alleged rail conspiracy could have been plotted from its territory . Western intelligence has long thought any Al Qaeda 's operatives in Iran are under strict control . al Qaeda interest in attacking railroads underscored following death of Peter Bergen .
Canadian authorities suspect al Qaeda elements in Iran provided guidance to alleged plotters . Iran has denied the alleged rail conspiracy could have been plotted from its territory . Western intelligence has long thought any al Qaeda operatives in Iran are under strict control . Al Qaeda 's interest in attacking railroads underscored following death of Osama bin Laden .