The head of the UN agency giving aid to Palestinians, Philippe Lazzarini, has accused Israel of stopping humanitarian assistance from reaching the north of the war-torn Gaza Strip. “The Israeli authorities continue to deny humanitarian missions to reach the north with critical supplies including medicine and food for people under siege,” wrote Lazzarini, the head of the United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA). Injured people could not be treated because the hospitals had no electricity after being hit, he wrote. “Remaining shelters are so overcrow…