The International Committee of the Red Cross (ICRC) slammed the "utter contempt" for humanity shown by all sides in Iraq amid fierce fighting in Falluja.
Residents who fled the city gathered at a cemetery near the town of al-Saqlawiya, north of Falluja, in an attempt to identify the bodies. The Central Committee for Relief Aid transported the corpses by truck to the cemetery.
Fighting continues in Falluja, despite claims by US marines that they have wiped out "insurgents".
Pierre Kraehenbuehl, the ICRC's director of operations, said, "We are deeply concerned by the devastating impact that the fighting in Iraq is having on the people of that country.
"As hostilities continue in Falluja and elsewhere, every day seems to bring news of yet another act of utter contempt for the most basic tenet of humanity: the obligation to protect human life and dignity," he said.
"For the parties to this conflict, complying with international humanitarian law is an obligation, not an option," Kraehenbuehl said in an unusually tough statement by the relief agency.
The ICRC called for aid agencies
to be allowed to assist Iraqis
The statement said there is an absolute prohibition on the killing of persons who are not taking active part in hostilities or have ceased to do so. It is also prohibited to torture them or to subject them to any form of inhumane, humiliating or degrading treatment.
They also imposed protection for the wounded as well as for civilians, the Red Cross agency underlined.
Aid workers killed
The senior Red Cross official said the killing this week of a wounded "insurgent" by a US soldier and the death of aid worker Margaret Hassan, who was killed by her kidnappers, had shocked the world.
As aid agencies were prevented from entering Falluja, Kraehenbuehl appealed "for everything possible to be done to allow such organisations to come to the aid of the thousands of Iraqis who are suffering."
The ICRC pulled its international staff out of most of Iraq and pared down operations there after a car bomb exploded outside its headquarters in Baghdad in October 2003, killing 12 people.