Explosive booby trap
Booby traps are dangerous, especially a bomb, hidden somewhere that looks safe [Cambridge Dictionary].
It is any device or material designed, constructed, or adapted to kill or injure. It functions unexpectedly when someone disturbs or approaches a harmless object or performs a safe act. Booby traps include manually-emplaced devices designed to kill, injure or damage and actuated by remote control or automatically after a lapse. Precise rules prohibit their use.
A booby trap is originally a schoolboy prank; the more lethal sense developed during World War I [Online Etymology Dictionary].
Booby. Online Etymology Dictionary. Retrieved from: https://www.etymonline.com/word/booby
Protocol on Prohibitions or Restrictions on the Use of Mines, Booby–Traps and Other Devices, as amended on 3 May 1996 (Protocol II to the 1980 Convention). (1996). Retrieved from: https://ihl-databases.icrc.org/en/ihl-treaties/ccw-amended-protocol-ii-1996
Booby trap. Cambridge Dictionary. Retrieved from: https://dictionary.cambridge.org/dictionary/english/booby-trap