Perfect example why banning firearms from a country will not prevent mass murder events.
China has people going on stabbing sprees as well.
Ban all knives and people will just find a way to poison people en masse. Or they will just use their truck to run people over. Or they will make a homemade explosive and blow people up. etc...
It's not a matter of what tools people have available to them. It's a matter of what makes them go postal in the first place.