JERUSALEM (AP) Israels military on Friday directed the evacuation of northern Gaza, a region that is home to 1.1 million people about half of the territorys population within 24 hours, a U.N. spokesperson said.

This could signal an impending ground offensive, though the Israeli military has not yet confirmed such an appeal. On Thursday it said that while it was preparing, a decision has not yet been made.

The order, delivered to the U.N., comes as Israel presses an offensive against Hamas militants. U.N. spokesperson Stphane Dujarric called the order impossible without devastating humanitarian consequences.

Earlier, the Israeli military pulverized the Gaza Strip with airstrikes, prepared for a possible ground invasion and said its complete siege of the territory which has left Palestinians desperate for food, fuel and medicine would remain in place until Hamas militants free some 150 hostages taken during a grisly weekend incursion.

A visit by Secretary of State Antony Blinken, along with shipments of U.S. weapons, offered a powerful green light to Israel to drive ahead with its retaliation in Gaza after Hamas deadly attack on civilians and soldiers, even as international aid groups warned of a worsening humanitarian crisis. Israel has halted deliveries of basic necessities and electricity to Gazas 2.3 million people and prevented entry of supplies from Egypt.

Not a single electricity switch will be flipped on, not a single faucet will be turned on and not a single fuel truck will enter until the Israeli hostages are returned home, Israeli Energy Minister Israel Katz said on social media.