The UN Relief and Works Agency is systematically providing political cover to Hamas, a senior government official told The Jerusalem Post on Tuesday, lashing out at the agency for passing a Hamas letter to US Sen. John Kerry when he visited Gaza last week. UNRWA head Karen AbuZayd gave the letter to Kerry, along with other material, during his brief visit Thursday to the Gaza Strip. The letter, written by a Hamas Foreign Ministry adviser and later disavowed by the Islamist group, was addressed to US President Barack Obama. Kerry, the chairman of the Senate Foreign Affairs Committee, handed the unopened letter to the US Consulate in Jerusalem. Kerry told Fox News that he never read the letter because it was sandwiched among other promotional papers the UN had given him. "Unfortunately, there is a pattern here," the senior Israeli official said. "That no one finds it strange that UNRWA, whose mandate is humanitarian, is the vehicle through which Hamas passes messages on to the US, just shows where UNRWA is at." Furthermore, the official said, UNRWA was lobbying around the world for governments to drop the international community's three preconditions to talking with Hamas - that it recognize Israel, disavow terrorism and accept previous Palestinian-Israeli agreements. It is not clear how this, or calls by UNRWA for an "independent international investigation" into alleged Israeli war crimes in Gaza, fell within the organization's mandate, the official added. UNRWA spokesman Sammy Mshasha denied the allegations, saying the Israeli official should first check his facts. It was UN Secretary-General Ban Ki-moon himself, during his visit to Gaza, who called an investigation into IDF actions in Gaza, Mshasha said. As to the overall charge that UNRWA was speaking to international governments on behalf of Hamas, Mshasha said, "We are not in the business of supporting one side over the other. We are in the business of supporting Palestinian refugees and helping them." He denied UNRWA was lobbying on any party's behalf, saying the organization "is a specialized agency of the UN, mandated to aid and assist the Palestinian refugees in its five areas of operation." Regarding the Hamas letter given to Kerry, Mshasha said it was dropped at the gate of UNRWA's office and had the seal of the Palestinian Authority. "We just delivered it to the intended party. We did not open it. We are not in the business of opening other people's mail. We did not know the content," he said. UNRWA has also come under criticism from Israeli officials who say it is parroting the Hamas line. The senior Israeli official said that during Operation Cast Lead, UNRWA adopted Hamas's position of calling for a cease-fire without any preconditions, such as an end to the weapons smuggling and the missile fire on Israel. "They just echoed Hamas's positions," the official said. Likewise, the official said that the organization was very critical of Israel's actions during the war. At one point, UNRWA spokesmen indicated that at least 40 refuge-seeking civilians were killed on January 6 in a UNRWA school facility in Jabalya. Christopher Gunness, the UNRWA spokesman, said on January 7 in an interview on the Democracy Now radio program, "Well, first of all, for the attack at Jabalya, we said yesterday 30 confirmed fatalities and 55 injured, including 15 critically. Very sadly, overnight, 10 people passed away. "The fatality figure has now risen from 30 to 40," he said then. "The people in the compound, over 1,300 people - by the way, some of those, many of them had been told by the Israeli army to leave their houses and move to a safe place. Of course, Gaza is unique in being a war with a fence around it. "But they nonetheless came - frightened, terrified, vulnerable - to our center. They were coming to what they thought was a neutral United Nations shelter, and then the rest is history - 40 people killed." According to the Israeli official, this was an example of how UNRWA routinely and uncritically adopted Hamas' narrative and claims of casualties. According to the IDF, only three civilians and eight to 10 Hamas gunmen were killed near the school. The IDF said that an IDF unit that came under fire from a Hamas cell near the school returned fire. No shell hit the school. The UN issued a revised report earlier this month admitting that as the result of a "clerical error," it was mistaken when it reported that the compound itself was shelled. Gunness has told the Post in the past that UNRWA never stated that the shell hit the school, but rather always spoke in more general terms of the casualties in the area. Mshasha said the charges leveled by the Israeli official "undermines our work and makes it that much more difficult." This type of criticism "creates the impression among the public at large that UNRWA will take sides. UNRWA does not take sides. It delivers humanitarian aid. It will be a beautiful day in Gaza when we turn our attention away from immediate humanitarian aid to human development," Mshasha said. UNRWA provides 900,000 Palestinian refugees with basic food supplies. "We do not support terrorism. We do not condone it," Mshasha said, adding that UNRWA has spoken out against the Palestinian rocket attacks on civilians living in southern Israel. "It is in the same breath that we condemn the Israeli army actions that violate international law," he said.