The UN's secretary general has called for an immediate ceasefire as Israel's pounding of Gaza enters its sixth day.
Ban Ki-moon said he was going to Cairo to join talks about a possible truce.
Sunday was the bloodiest day of Operation Pillar of Defence, as Israel said it was targeting the homes of Hamas militants.
Eighty Palestinians and three Israelis have died in six days, as Israel hits Gaza from the sea and air while Hamas militants fire rockets.
Israeli Prime Minister Benjamin Netanyahu said he was ready to expand the operation, after Israel authorised the mobilisation of up to 75,000 army reservists.