JERUSALEM (AFP) - Israel's army violated codes of ethics and international law during the war in Gaza by attacking medics and refusing to allow the treatment of wounded, a human rights group charged on Monday. The actions reflect a "demonisation of Palestinians (which) bears a heavy price for Israeli society," warned a report by Physicians for Human Rights that called for an independent body to investigate the military's conduct during its 22-day Operation Cast Lead in Gaza that ended on January 18. The Israeli army said it had not yet concluded its investigation, but that fighters from Gaza's ruling Hamas movement had battled under cover of ambulances and medical facilities. Among the offences listed by the Israeli non-governmental organisation are "attacks on medical personnel; damage to medical facilities and indiscriminate attacks on civilians not involved in the fighting." "Israel placed numerous obstacles in the course of the operation that impeded emergency medical evacuation of the sick and wounded and also caused families to be trapped for days without food, water and medications," the report said. "The actions ... violate directives of international law which forbid attacks on medical centres and medical teams during fighting" and "blatantly violated codes of ethics." During the offensive, Israeli fire killed 16 Palestinian medical personnel and wounded 25 others while eight hospitals and 26 primary care clinics were attacked, according to figures from the United Nations and the group. Among the specific incidents cited is that of a Mr. Shurrab whose two sons were shot by Israeli forces while the trio drove toward the southern city of Khan Yunis on January 16. "One of the sons died immediately, the other bled to death for 12 hours," it said. "All that time the Israeli soldiers were within a short distance from the Shurrabs but did not provide any assistance despite the father's repeated requests." Such incidents reflect a general demonisation of Palestinians, a process that "reached its nadir when soldiers in an army that flaunts its morality declined to help evacuate injured civilians and trapped families, when soldiers acted in a trigger-happy manner as they opened fire on ambulances, medical installations and medical personnel." "We have noticed a stark decline in IDF (Israeli Defence Forces) morals concerning the Palestinian population of Gaza, which in reality amounts to a contempt for Palestinian lives," said Dani Filc, the chairman of the group. "It is critical that the investigation of Operation Cast Lead is completed by a neutral, external investigator without ties to the IDF." The army said that it was investigating the claims in a "thorough" manner and said its forces were instructed to "act with the utmost caution in order not to cause harm to medical vehicles and medical facilities." "Throughout the fighting, Hamas methodically made use of medical vehicles, facilities and uniforms in order to conceal and camouflage terrorist activity, and in general used ambulances to carry terror activists and weapons," it said in a statement. "Hamas used ambulances to 'rescue' terror activists from the battlefield and used hospitals and medical facilities as hiding places." Such actions "greatly complicated the coordination of rescue and medical evacuation. "It must be emphasised that under international law, the protections afforded to medical teams or 'protected institutions'... cease to exist when these medical teams or institutions are not used for humanitarian purposes rather for carrying out actions intended to harm the State of Israel," the statement said. Meanwhile, army chief of staff Lieutenant General Gabi Ashkenazi on Monday dismissed separate allegations of wanton killing of civilians during the Gaza offensive, based on soldiers' testimonies published last week. "I do not believe that IDF troops hurt Palestinian civilians in cold blood," Ashkenazi said in a speech. "We will wait the outcome of an investigation, but my impression is that the IDF acted morally and if such cases did take place they were isolated."