GAZA CITY, Gaza — Israel ignored mounting international calls for a cease-fire Monday and said it won't stop its crippling 10-day assault until "peace and tranquility" are achieved in southern Israeli towns in the line of Palestinian rocket fire.
Israeli forces seized control of high-rise buildings and attacked smuggling tunnels and several mosques in a relentless campaign against Hamas militants that took an increasing toll on civilians. The United Nations said at least 500 people have died in the Gaza fighting, about a quarter of them civilians.
Israel also suffered casualties. Late Monday, three Israeli soldiers were killed by what Israeli officials said was an errant tank round from one of its own guns.
Arab delegates met with the U.N. Security Council in New York, urging members to adopt a resolution calling for an immediate end to the attacks and a permanent cease-fire. At the same time, diplomats and European leaders traveled the region in an effort to stop Israel's expanding ground and air offensive.
In a serious urban clash, Israeli troops and Hamas militants fought a gunbattle on the outskirts of the crowded Gaza City neighborhood of Shajaiyeh, Israeli defense officials said. Details also emerged of an unsuccessful attempt by Hamas fighters to capture Israeli soldiers hours after the ground operation began Saturday with a withering round of artillery fire.
Military spokesman Brig. Gen. Avi Benayahu told Israeli TV the assault was going according to plan with forces sweeping through Palestinian rocket launching locations near the border.
Despite Israeli claims that casualties have been heavy among militants, no injured Hamas fighters were seen Monday by an Associated Press reporter at Shifa Hospital, the Gaza Strip's largest. Instead, the hospital was overwhelmed with civilians. Bodies were two to a morgue drawer, and the wounded were being treated in hallways because beds were full.
At least 20 Palestinian children were killed during the day Monday, said Dr. Moaiya Hassanain, a health official. Most confirmed deaths have been civilians.
Three brothers died in an attack on a town outside Gaza City, a Gaza health official said. They were carried to a cemetery in an emotional funeral. One of them, Issa Samouni, 3, was wrapped in a white cloth, showing only his pale, yellow face. A man delicately placed him in a dark grave cut into the earth.
Later, five civilians were killed when a shell fired by an Israeli ship hit their house on the Gaza shore, hospital officials said. Palestinians said Israeli attacks intensified before dawn Tuesday.
Gaza health officials reported that since the campaign began on Dec. 27 more than 550 Palestinians have been killed and 2,500 wounded, including 200 civilians. U.N. humanitarian chief John Holmes put the Palestinian toll at 500, with about 125 of them civilians.
Holmes called the Gaza strife an "increasingly alarming" humanitarian crisis, directly contradicting Israeli denials that its offensive caused the growing problem. He said Gaza is running low on clean water, power, food, medicine and other supplies since Israel began its offensive. Israeli leaders have maintained there is no humanitarian crisis, and that they have been delivering vital supplies.
Late Monday, the Israeli military said three soldiers were killed and 24 others wounded by friendly fire when a tank shell hit their position outside Gaza City. The military said a colonel who commanded an infantry brigade was among the injured.
Israeli defense officials said earlier that one soldier was killed when soldiers fought off an attempt by Hamas fighters to capture Israeli soldiers hours after the ground operation began. They said the infantrymen were advancing up a strategic hill before dawn Sunday when militants emerged from a tunnel and tried to drag two Israeli infantrymen inside.
Hamas already holds one Israeli soldier, captured in June 2006, and another would be an important bargaining chip.
That death and the three soldiers killed by friendly fire brought to eight the number of Israelis killed since the offensive began. One other soldier and three civilians were killed during the initial air phase of the offensive. Israeli officials are concerned that heavy casualties amoung its troops could undermine what has so far been overwhelming public support for the operation.
In Shajaiyeh, troops seized control of three six-story buildings on the outskirts, climbing to rooftop gun and observation positions, Israeli defense officials said. Residents were locked in their rooms and soldiers took away their cell phones, a neighbor said, quoting a relative who called before his phone was seized.
"The army is there, firing in all directions," said Mohammed Salmai, a 29-year-old truck driver. "All we can do is take clothes to each other to keep ourselves warm and pray to God that if we die, someone will find our bodies under the rubble."
Fighter jets attacked houses, weapons storage sites, a pair of mosques and smuggling tunnels, as they have since the start of the offensive. Israel has attacked several mosques during the campaign, saying they were used to store weapons.
In another strategic move, Israeli forces seized a main highway in Gaza, slicing the territory in two.
Israeli forces detained 80 Palestinians — some of them suspected Hamas members — and transferred several to Israel for questioning, said military officials, speaking on condition of anonymity because they were not allowed to release the information.
The Gaza City area was rocked by shelling from both sides as gunboats in the sea and artillery and tanks closing in from the east unloaded thunderous fire.
After dark, the shelling reached deeper into residential areas. Fireballs lit up the horizon to the east, setting off blazes on the ground and silhouetting Gaza's tall buildings. Tracer fire ripped across the skyline.
The State Department said the U.S. was pressing for a cease-fire that would include a halt to rocket attacks and an arrangement for reopening crossing points on the border with Israel, said spokesman Sean McCormack. A third element would address the tunnels into Gaza from Egypt through which Hamas has smuggled materials and arms.
President George W. Bush emphasized "Israel's desire to protect itself."
"The situation now taking place in Gaza was caused by Hamas," he said.
The deputy head of Hamas' politburo in Syria, Moussa Abu Marzouk, rejected the U.S. proposal, telling the AP the U.S. plan seeks to impose "a de facto situation" and encourages Israel to continue its attacks on Gaza.
Europe "wants a cease-fire as quickly as possible," Sarkozy said after meeting Abbas, urging Israel to halt the offensive, while blaming Hamas for acting "irresponsibly and unpardonably."
"The EU insists on a cease-fire at the earliest possible moment," said Karel Schwarzenberg, the foreign minister of the Czech Republic, which took over the EU's presidency last week from France. Rocket attacks on Israel also must stop, Schwarzenberg told a news conference with Livni.
The EU brought no truce proposals of its own because the cease-fire "must be concluded by the involved parties," he added.
As the bruising campaign entered its 10th day Monday, Hamas pummeled southern Israel with more than 30 rockets and promised to wait for Israeli soldiers "in every street and every alleyway."
Israeli Defense Minister Ehud Barak said the offensive would go on until Israel achieved "peace and tranquility" for residents of southern Israel.
One of the rockets struck a large outdoor market that was closed at the time in the town of Sderot, just across Gaza's northeastern border. Another hit a kindergarten in the coastal city of Ashdod, north of the strip. The kindergarten, like schools across southern Israel, was closed and empty because of the rocket threat.
Israel has three main demands: an end to Palestinian attacks, international supervision of any truce, and a halt to Hamas rearming. Hamas demands an end to Israeli attacks and the opening of border crossings to vital cargo.
Livni said the operation was designed to change the rules of Israel's struggle against Hamas after years of firing rockets at Israel. From now on, she said, "when Israel is targeted, Israel is going to retaliate."
Israeli military spokeswoman Maj. Avital Leibovich said Hamas was to blame for civilian casualties because it operates in densely populated areas.
"If Hamas chose cynically to use those civilians as human shields, then Hamas should be accountable," she said.
Hamas leader Mahmoud Zahar exhorted Palestinians to fight the Israeli forces and target Israeli civilians and Jews abroad.
"The Zionists have legitimized the killing of their children by killing our children. They have legitimized the killing of their people all over the world by killing our people," Zahar said in a grainy video broadcast on Hamas TV.
Israel's operation has sparked anger across the Arab world and has drawn criticism from countries such as Turkey, Egypt and Jordan, which have ties with Israel and have been intimately involved in Mideast peacemaking.
Barzak reported from Gaza City, Keyser from Jerusalem.