Public International Law (Vol. I & II)
Article 15
At all times, and particularly after an engagement, Parties to the conflict shall, without delay, take all possible measures to search for and collect the wounded and sick, to protect them against pillage and ill-treatment, to ensure their adequate care, and to search for the dead and prevent their being despoiled.
Whenever circumstances permit, an armistice, suspension of fire, or local arrangements shall be made to permit removal, exchange, and transport of the wounded left on the battlefield and to permit the passage of medical and religious personnel and equipment.