Gaza crisis: UN's Ban Ki-moon calls for ceasefire
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-six Palestinians and three Israelis have died in six days, as Israel hits Gaza from the sea and air while Hamas militants fire rockets.
Israel's army said it had targeted around 80 sites overnight, including militant-owned buildings, weapons storage facilities and police stations, bringing its total to 1,350 sites targeted since Wednesday. Palestinian sources said 18 people had been killed in the raids.Ban Ki-moon calls for Gaza truce
It added that one rocket had been fired out of Gaza towards Israel overnight - more rocket fire is resuming now but there are no reports of casualties or damage.
Israeli Prime Minister Benjamin Netanyahu said on Sunday he was ready to expand the operation, after Israel authorised the mobilisation of up to 75,000 army reservists.
Egyptian President Mohammed Mursi has said an Israeli ground invasion would have "serious repercussions", saying Egypt would never accept it "and neither will the free world".
The Arab League, which met in emergency session in Cairo on Sunday, is sending a delegation of foreign ministers to Gaza on Tuesday.
Wrong house hit?
Egypt has been leading efforts to broker a peace deal, with both senior Israeli and Hamas officials in Cairo for talks.
But while the sides may be talking, there is no suggestion they might be about to settle on cease-fire terms, says the BBC's Jon Leyne in Cairo.
And while they discuss possible agreements, the bloodshed north of the border continues.
The bombardment of Gaza carried on in the early hours of Monday with one blast destroying a Hamas police headquarters.
Few people in Gaza would have got much sleep, says the BBC's Jon Donnison in Gaza City: as well as air strikes there was the rhythmic thud of shelling from Israeli war ships.
At least nine children were killed on Sunday, and TV reports showing horrific images of their burned and bloodied bodies has been fueling Palestinian anger, adds our correspondent.
On Sunday, one strike on the Gaza City house of Hamas policeman Mohamed Dalou killed at least nine members of his family.
Mr Ban said he was deeply saddened by the deaths of the Dalou family and other Palestinians, while expressing alarm at the continued rocket fire from Gaza against Israeli towns.
"This must stop," he said in a statement released late on Sunday. "I strongly urge the parties to co-operate with all efforts led by Egypt to reach an immediate cease-fire."
Hamas's military wing said earlier: "The massacre of the Dalou family will not pass without punishment."
The chief military spokesman for Israel's Defense Forces (IDF), Yoav Mordechai, told Israel's Channel 2 TV that the intended target of the strike had been Yehiya Rabiah, the head of Hamas's rocket-launching unit, but that there had been "civilian casualties".
Israel's Haaretz newspaper quoted IDF officials as saying the strike had hit a neighbour's house by mistake because of a "technical error". The IDF said it did not know what the Haaretz source was, but was looking into the report.
The charity Save the Children has said families in Gaza are running out of food and water, with most trapped in their homes, enduring power cuts of up to 18 hours a day.
Israel's army says 105 missiles fired from Gaza hit Israel on Sunday, while another 41 were intercepted by its Iron Dome missile defence system, including at least one over Tel Aviv.
The Israeli ambulance service reported two people were seriously injured, with 10 moderately or lightly hurt.
Since the conflict began, Gaza militants fired 848 rockets towards Israel - 546 hit Israel, 302 were interecepted by the Iron Dome interceptions, the IDF says.
Before the recent offensive, Israel had repeatedly carried out air strikes on Gaza as Palestinian militants fired rockets across the border.
But the aerial and naval bombardment is its most intense assault on the territory since Israel launched a full-scale invasion four years ago.
The current violence is nowhere near the scale of that war, says BBC Middle East Editor Jeremy Bowen.
But if the plaintive calls for what the Americans and British are calling de-escalation continue to be ignored by both sides, it could go the same way, he adds.
Hamas seized control of Gaza in 2007, a year after winning a decisive victory in general elections. Israel withdrew from the strip in 2005 but maintains a blockade.
Israel, as well as the United States and the European Union, regards Hamas as a terrorist organisation.