Related Rule
Nigeria
Practice Relating to Rule 64. Conclusion of an Agreement to Suspend Combat with the Intention of Attacking by Surprise the Adversary Relying on It
Nigeria’s Manual on the Laws of War states that “informing the enemy that there is an armistice in order to make him leave his position” is an “illegitimate tactic”. 
Nigeria, The Laws of War, by Lt. Col. L. Ode PSC, Nigerian Army, Lagos, undated, § 14.
I
The manual also states that “violation of surrender terms” is a war crime. 
Nigeria, The Laws of War, by Lt. Col. L. Ode PSC, Nigerian Army, Lagos, undated, § 6.