The new phase of Israel’s assault began at night with a huge wave of airstrikes as ground forces entered the north of Gaza. Tanks and infantry moved in and Israel says its commandos are operating on the ground across the north of the territory.
Israel's Prime Minister Benjamin Netanyahu told his nation: “The war inside the Gaza Strip will be difficult and long and we are prepared for it. This is our second war of independence. We will fight for the defence of the homeland.”
The Palestinian authorities said at least 400 more people had been killed in Gaza on the first day of the full ground offensive.
As the assault began, Israel cut off all internet and phone communications in Gaza. Aid agencies and the United Nations reported that they were no longer able to communicate with their staff or confirm their safety.
Reeta Chakrabarti presents BBC News at Ten. Reporting by Jeremy Bowen in southern Israel and Rushdi Abualouf in Gaza.