Israeli leaders said its offensive in Gaza will continue until the country's aims are met as military sources and witnesses reported that Israeli troops and Hamas militants fought their first major battles in Gaza City.
Gaza City has been pounded from air and sea and now sees fighting in its streets
Large explosions and heavy exchanges of fire rocked Shejaiya neighborhood of eastern Gaza City as Israel pressed its campaign to halt Hamas rocket attacks.
Hamas said in a statement that its fighters had fired missiles at seven tanks in the same district. The Islamic Jihad movement said several of its members were killed in the fighting.
Israeli military sources confirmed that troops were involved in heavy clashes in that area.
Flares lit up the skies over the blacked-out neighborhood. Assault helicopters were also seen.
Palestinians said Israeli shelling killed at least 29 Gazan civilians in the Strip, 17 of them children from three families
The Israeli army refused to give updated casualty figures from the day's fighting, saying a toll would only be released once a day, in the evening.
But according to Israeli media reports, which could not therefore be confirmed, some 55 soldiers have been wounded since Saturday night, when the troops first crossed into the Gaza Strip in the second stage of Operation "Cast Lead," following a week of incessant air attack.
On Sunday, one Israeli soldier was killed.
Ceasefire calls rebuffed by Israel
Gaza has been reduced to rubble by Israel's assault
Israeli Foreign Minister Tzipi Livni rebuffed European Union calls for a ceasefire, saying at a joint news conference with EU representatives that while Israel did not request world countries to help it fight Hamas, it wanted them "to let us continue (fighting) until we decide we've achieved our aims."
She said Israel was fighting to create a "new equation" whereby it would no longer act with restraint when Hamas fired rockets from the Gaza Strip.
Defense Minister Ehud Barak said Monday, as he prepared to brief the Knesset Foreign Affairs and Defense Committee, that the Gaza offensive would continue since Israel had yet to achieve its objectives.
French President Nicolas Sarkozy was also due in Israel for talks with officials, as the international community kept up its pressure for a ceasefire in the fighting, which began December 27, when Israel, after a week of massive rocket barrages from the Gaza Strip on southern Israeli towns and cities following the end of a nervous six- month truce, began a campaign of airstrikes at Gaza targets.
Barak said Monday that Gaza City was partially surrounded by Israeli troops, who on Sunday took up positions which effectively cut the salient into two.
Local residents said tanks moved into the city's Zaytoun neighborhood from a base they set up at a former Jewish settlement, Netzarim, south of the metropolis.
Occupying a hill overlooking Gaza City and the camp, they also moved toward the eastern outskirts of Jabaliya, north of the city and one of the most crowded refugee camps in the enclave.
The troops' advance sparked heavy clashes with local Hamas fighters.
Palestinian officials reveal Gaza toll
According to Palestinian officials, since the start of the ground offensive began after darkness fell on Saturday, at least 50 Palestinians have been killed. More than 200 have been injured.
Foreign Minister Livni says Israel will decide when to stop
During the fighting Monday, a tank shell destroyed a house during fighting in Zaytoun neighborhood before dawn, killing 13 members of one family, Assamouni, including the father, mother and eight children aged four to 15, hospital officials said. Ambulances were able to reach the house only after daylight, witnesses said.
A naval shell later also struck a house in western Gaza City's Beach refugee camp Monday morning, killing a father, mother and five children of another family, the Abu Aishais, the chief of the emergency room of Gaza City's Shifa hospital, Haythem Dababish, told the DPA news agency.
In Beit Hanoun, in northern Gaza city near the border with Israel, four more civilians died when a tank shell hit a mourning tent set up near the home of a paramedic killed Sunday, the town's hospital said.
In the evening, an Israeli airstrike on eastern Gaza City killed a mother and four children.
Keeping up the pressure, Israeli fighter jets meanwhile struck some 30 more targets in the coastal enclave overnight, the military said.
Israeli ground troops, who entered the strip late Saturday have also taken control of some areas from which Palestinian militants have been firing rockets at southern Israel.
Nonetheless, rockets continued to land Monday, with about 30 striking various locations in Israel, including one which slammed into a kindergarten, which was empty at the time, in the port city of Ashdod, about 30 kilometers north of the Strip.
Since Israel nine days ago launched Operation "Cast Lead" -- aimed at curbing seven years of rocket and mortar attacks against its southern towns and villages -- 537 Palestinians have been killed and at least 2,600 injured, 800 of the critically.
Four Israelis - three civilians and a soldier - have been killed in the 480 rockets and mortars which have been launched from the salient since the operation began. Also, 119 civilians have been wounded, in addition to many more who have been treated for shock.
Meanwhile, the humanitarian situation in the Gaza Strip is quickly worsening according to residents.
Civilians without electricity, with little water and food
Israel has thrown a ring of steel around Gaza
Residents of Gaza City, who have been without electricity for days, say they have only small amounts of drinking water. With even candles now a scarce commodity, Gaza City residents sit in the dark - many of them in winter coats as they keep windows open to avoid glass shards flying inside their homes from a possible nearby blast.
Hospitals are running on unreliable emergency generators. On top of that, with the large influx of casualties - unprecedented in at least five decades of the conflict - those hospitals are in urgent need of blood units, anesthetics, strong painkillers, tetanus vaccines and even body bags and sheets, according to the Red Cross.
The salient's power plant -- supplying large parts of Gaza City and the north of the strip -- has shut down for lack of industrial fuel. Six out of 10 power lines from Israel and one of two power lines from Egypt, which supply the rest of the strip, have been damaged in the Israeli strikes.
Many types of food are hard to get buy, including bread. Only two bakeries remain open in Gaza City, with queues stretching all the way down the street. After venturing outdoors and waiting in line for hours on end, each customer can get one plastic bag with 50 small pita breads. Prices have nearly doubled since the offensive began.
Large parts of the strip also have no tap water, as power blackout mean pumps are not working.
A few supermarkets remain open. But many basic items, including dairy products and toilet paper, are missing from the shelves.
Some 80 percent of the strip's population of 1.5 million residents relies on food parcels handed out by UN and international organizations containing basic items, including rice, flower and oil. But those groups say they have had a hard time distributing their parcels amid the ongoing airstrikes and ground combat.
Israel, for its part, says that while civilian populations are affected in times of combat, it is doing what it can to avoid a humanitarian crisis.
"Currently there is no such (humanitarian) calamity," the Israeli Foreign Ministry insisted in a statement Monday.
The ministry pointed out that, since the Gaza offensive began, the Kerem Shalom border crossing with southern Gaza has been open to daily humanitarian aid, allowing in more than 400 trucks with 10,000 tons of supplies in the first week.
Some 2,000 units of blood donated by Jordan and 10 ambulances donated by Turkey and the Palestinian Red Crescent in the West Bank also passed through the crossing, while 20 Palestinians were evacuated to hospitals in Israel.
UN urges Israel to allow in more aid
Conditions for civilians in Gaza are deteriorating fast
The United Nations says it is not enough. Before Hamas took control of the Gaza Strip in June, and under an EU-Palestinian- Israeli agreement from November 2005, some 475 trucks entered Gaza each day, noted the UN's Office for the Coordination of Humanitarian Affairs (OCHA).
Philippe Lazzarini, OCHA's head in the Palestinian areas, urged Israel to also open also its Karni crossing for commercial goods and allow in more supplies, as Kerem Shalom can handle only up to 100 trucks a day. He also urged Israel to accept a humanitarian truce to allow Gazans "a breathing space" and pick up their food aid without running risks to their personal safety.
"By any standard there is a humanitarian crisis in Gaza," he told the DPA news agency. "It's an unprecedented crisis for the people in Gaza. People are hungry, people are cold and people feel fear all the time."