I lived in Ireland during "The Troubles". This sort of thing was common. Another way of dealing with bomb threats was drive the plane away from the terminal, down a taxiway and then make everyone get off the plane, take all the luggage out of the plane and then make everyone identify their suitcases. If there was a suitcase left over, everyone and every suitcase got off the plane again. If the suitcase was still there the second time, the Army took the suitcase and blew it up.

In Belfast, you left your shopping bags outside of stores (because the IRA would hide bombs in shopping bags and leave them to explode inside stores). No one would steal your bags because they might be bombs.