Israeli troops are reported to be fighting Hamas in the heart of Gaza City.
Thousands of Israeli soldiers have been sent to the war in Gaza.
Meanwhile dozens of Palestinians have been reported killed by Israeli air strikes in the southern Gazan cities of Khan Younis, Rafah and Deir al-Balah.
The United Nations has again raised concern about civiilian casualties. It said an average of 160 children are being killed each day in Gaza.
Clive Myrie presents BBC News at Ten reporting from the frontline, with one Israeli artillery unit preparing to go into battle, and from Yogita Limaye on the Palestinian civilians facing daily bombardment by Israeli forces.
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