Соответствующая норма
Practice Relating to Rule 64. Conclusion of an Agreement to Suspend Combat with the Intention of Attacking by Surprise the Adversary Relying on It
Spain’s Military Criminal Code (1985) punishes any soldier “who violates a suspension of arms, an armistice, a capitulation or another agreement concluded with the enemy”. 
Spain, Military Criminal Code, 1985, Article 72.
Spain’s Penal Code (1995) punishes “anyone who violates a truce or an armistice concluded between the Spanish Nation and the enemy or between their belligerent forces”. 
Spain, Penal Code, 1995, Article 593.
Spain’s Penal Code (1995), as amended in 2010, states:
Anyone who [commits any of the following acts] during armed conflict shall be punished with three to seven years’ imprisonment:
9. Violating a cease fire, the terms of an armistice, capitulation or any other agreement concluded with the adverse party. 
Spain, Penal Code, 1995, as amended on 23 June 2010, Article 612(9).