Aid agencies said Monday they have resumed relief operations in Gaza, but fighting still prevents them from evacuating the sickest people and reaching all those who need help. [...] As many 88 percent of Gaza's residents now require food aid, said Helene Gayle, president of the relief organization CARE USA. The three-hour lull in fighting that Israel allows for humanitarian aid to move around Gaza is not sufficient, she said. "Food distribution takes a minimum of five hours under normal circumstances, so three hours with no guarantee of safety is woefully inadequate for us to do our job," she said in a conference call with reporters. [...] The World Food Program handed out 1,200 monthly food rations to people in Gaza and 1,400 emergency bread packages Sunday, said spokeswoman Emilia Casella. But the agency has been unable to reach many people who need food, she said.