The U.N. Palestinian refugee agency called on Tuesday for a temporary truce to allow people to leave areas of northern Gaza as health officials said they were running out of supplies to treat patients hurt in a three-week-old Israeli offensive.

Israeli soldiers sit in a military vehicle near trucks carrying humanitarian aid that wait before making their way to the Gaza Strip, amid the ongoing conflict in Gaza between Israel and Hamas, at Erez Crossing in southern Israel,

Israeli forces are besieging hospitals and shelters, medics say. The Israeli military says Hamas has regrouped in the area.

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,