There is an obligation to collect and record civilian casualties, to protect the wounded and to care for the sick, as stated in Geneva Convention IV Relative to the Protection of Civilian Persons in Time of War, Articles 8 and 16.
Whenever circumstances permit and particularly after an engagement, all possible measures shall be taken, without delay, to search for and collect the wounded, sick and shipwrecked, to protect them against pillage and ill treatment, to ensure their adequate care, and to search for the dead, prevent their being despoiled, and decently dispose of them.
The wounded and sick, as well as the infirm, and expectant mothers, shall be the object of particular protection and respect.
There is an important limitation within this provision, that searching for civilian persons can only be conducted as far as military conditions allow. The omissions are evident, there is no obligation to arrange for a cease-fire to collect the casualties and there is no obligation to record these casualties.
DISCUSSION PAPER 2: DRONE ATTACKS, INTERNATIONAL LAW, AND THE RECORDING OF CIVILIAN CASUALTIES OF ARMED CONFLICT, p. 16