Israeli infantry made their first raids into the Gaza Strip on Friday since Hamas fighters rampaged through southern Israel, and Prime Minister Benjamin Netanyahu said a campaign of retaliation had only just begun.

Israel has vowed to annihilate Hamas after its fighters burst out of Gaza a week ago and stormed through towns and villages, killing 1,300 Israelis, mainly civilians, and making off with scores of hostages.

Since then Israel has placed the Hamas-run Gaza Strip, home to 2.3 million Palestinians, under a total siege and bombarded it with unprecedented air strikes. Gaza authorities say 1,900 people have died.

On Friday Israel gave more than a million residents of the northern half of Gaza 24 hours to flee to the south to avoid an onslaught. Hamas vowed to fight to the last drop of blood and told residents not to go.