Israeli ground forces backed by air and naval power fought their way into urban areas deep inside the Hamas-ruled Gaza Strip yesterday, striking at the Palestinian group's hide-outs and rocket-launching sites but also inflicting a heavy toll in civilian lives.
Medical authorities in Gaza said 16 children were killed by airstrikes, naval shelling and artillery fire. Israel said it is aiming at Hamas' 15,000-member paramilitary force.
Late in the day, Israeli troops entered densely populated areas just north and east of Gaza City, the territorial capital. Witnesses said they took up rooftop positions on several six-story buildings on the outskirts of the city, which has a population of 400,000.
Israel continued to resist diplomatic efforts for an immediate halt to the assault as the fighting entered its 10th day. Israeli leaders said the fighting was inconclusive and could go on for days, if not weeks.
Hamas, too, vowed to keep fighting and fired at least 31 rockets into Israel yesterday, including one that struck an empty kindergarten in the city of Ashdod.
The Israeli offensive is aimed at halting years of rocket fire into southern Israel by Palestinian militants that terrifies tens of thousands of residents of the Jewish state. Hamas, an Islamic group whose charter calls for Israel's destruction, seized control of Gaza from its Palestinian factional rivals in mid-2007, two years after Israel unilaterally withdrew its settlements and military bases.
After a week of air raids, Israel sent tanks and troops into the 140-square-mile territory on Saturday.
As Israeli jets and warships bombarded the southern part of the strip, striking tunnels used to bring in weapons from Egypt, tank and infantry units punched into the north. They met limited resistance over the weekend while moving cautiously through open fields toward Hamas' urban strongholds a few miles away.
"Hamas did not seek a direct confrontation with our forces," Israeli Defense Minister Ehud Barak told a parliamentary committee yesterday morning. "They want to drag us into urban areas. The main test could still be ahead."
A spokesman for Hamas' military wing, using the nom de guerre Abu Obeida, warned Israel that militants "wait for you in every street and every alleyway."
Heavy air and artillery fire erupted after dark near Jabaliya as Israeli forces battled for control of a hill overlooking that city and its sprawling refugee camp.
Another heavy clash was reported in Shajaiyeh, on Gaza City's eastern outskirts.
The Israeli military said its forces have killed or wounded "dozens" of militants in the ground operation while losing one of its own soldiers.
Hamas has released no casualty figures, but Palestinian medical officials said civilians account for about half of the 125 deaths they have recorded since Saturday.
At least 550 Palestinians in Gaza have been reported killed in the past 10 days. About one-fourth of them are civilians, according to United Nations estimates.
Five Israelis have been killed in that period, including three civilians hit by cross-border rocket fire. A senior Israeli military official said the fighting in Gaza "is very complicated because there are a lot of tunnels, a lot of bunkers, a lot of booby traps."
Hamas has given few accounts of the fighting. Its leaders are in hiding and make sporadic appearances on Hamas TV. One leader, Mahmoud Zahar, surfaced in a grainy video yesterday, exhorting Palestinians to take revenge.
"The Zionists have legitimized the killing of their children by killing our children," he said. "They have legitimized the killing of their people all over the world by killing our people."
The bloodshed has spurred street protests around the world and brought diplomatic pressure on Israel.
Czech Foreign Minister Karel Schwarzenberg, heading a European Union peace mission, and French President Nicolas Sarkozy met separately with Israeli officials in Jerusalem to press for an immediate cease-fire.
"The guns must fall silent," Sarkozy said. "There must be a humanitarian truce."
Israeli Foreign Minister Tzipi Livni rejected the appeals, saying the military needed more time to subdue Hamas.