Terrorism can involve simulated violence used for political ends;
the violence does not even have to be real;
these drills are being used for political ends;
most will fall for the hoax, so the effect is the same.

https://www.youtube.com/watch?v=Dp1yIxCX7tw

Above is a clip of a proven hoax used for political ends.
Remember, if the event is real, there is no need to fake anything.