Bomb or attempted hijack.
The hijack was well controlled but not the bomb identified as not real.
There is no such thing as half emergency.
land as soon as possible.
Require and expect full ground support.
If no air stairs to disembark passengers then use the slides. This would be mentioned on the declaration of emergency , ie, require full services after landing and expect immediate aircraft evacuation .
Otherwise continue to destination airport without
emergency declaration.
There was a similar thread was on prune re SIA b777 wing fire, in Singapore when the ground staff fire services, convinced the cockpit crew only half an emergency existed. The passengers were held onboard against their will. they saw and knew a fire was raging outside in the entire right wing.
When the crew decided to return to departure airport immediately, ie land as soon as possible, to save time exposed to the threat, , they declare emergency Pan Pan call, and request high speed arrival without delay.
If there is no threat to the aircraft or passengers, then continue to destination.
No police presence is needed.
an emergency specific bomb threat, is promulgated in the regs.
Evacuate immediately after landing use air stairs if possible otherwise use emergency escape slides.
If a" specific bomb threat" is declared
the bomb was visible , take all precautions to protect passengers from an explosion.
The Bomb,s trigger could be time- clock switched, sensor movement, pressure sensor, remote trigger.all these must be taken as a serious threat to the passengers and aircraft.
No half emergency , to be considered.
The decision should be standard operating procedure.
( at any time)
If a passenger makes a " threat to the aircraft or crew " see your FAM procedures,
They MUST be removed from the aircraft, immediately .
no withdrawal of the "threat" is permitted at a later time saying "only a joke I was not serious."