The top United Nations official in Gaza said Friday that the organization is collecting evidence that white phosphorus was used in attacks on U.N. facilities during Israel's 22-day offensive. John Ging, the director of operations in Gaza for the United Nations Relief and Works Agency (UNRWA) was asked by reporters if he had seen the evidence of the use of white phosphorus collected by Amnesty International and other human rights groups. “Yes, and we've been doing it ourselves, as well, in terms of the evidence from our own installations,” he said. “We hope that what will happen is that it will feed into a credible and effective mechanism for accountability,” Ging added. The use of white phosphorus is legal if used as a smokescreen in open ground but is banned in civilian areas because it sticks to human skin and can burn through to the bone. The U.N. has said previously that it believes white phosphorus was used in the attack on its headquarters. “I think our people have said if it looks like white phosphorus, if it acts like white phosphorus, it must be white phosphorus,” Karen AbuZayd, UNWRA Commissioner-General, said Friday, according to the Associated Press Amnesty International issued a report Monday about a shelling in a residential area of Gaza City, concluding that Israel used the potentially deadly weapon improperly. “The Israeli army used white phosphorus, a weapon with a highly incendiary effect, in densely populated civilian residential areas of Gaza City, according to indisputable evidence,” the report said. The report said the organization's delegates in Gaza found burning white phosphorus around residential buildings Sunday that were endangering residents and property.