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Israeli strikes killed 23 people in the Gaza Strip on Wednesday, including 16 militants and a mother and her two young daughters, in the deadliest day of fighting since Israel withdrew from the coastal strip last year.

The violence, in which Palestinians said 76 people were wounded, came as Israel was embroiled in another deadly battle on its northern border with Hezbollah terrorists in Lebanon.

The fighting in Gaza began after Hamas-linked terrorists captured an Israeli soldier in a June 25 cross-border raid. Israel launched an offensive to rescue the soldier, but later expanded its aims to stop militants from firing rockets at Israeli towns.

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On Wednesday, Israeli aircraft, tanks, and artillery supported bulldozers that drove into northeastern Gaza, flattening orchards and greenhouses to deprive cover to militants firing rockets into Israel, the army said.

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Most of the militants killed were hit by tank fire, airstrikes and in clashes with Israeli troops in Gaza City. One militant was killed in northern Gaza by an artillery shell.

No Israeli soldiers were hurt in the fighting.

Sixteen of those killed were identified as militants by their Palestinian militant groups. A 3-year-old girl was also killed in Gaza City, hospital officials said. Two additional men were killed in Gaza City, but it was not clear if they were militants.

In northern Gaza, a woman and her two daughters — an 8-month-old baby and a 5-year-old — were killed when an artillery shell landed on their house, hospital officials said.

Another man was shot and killed near a no-go zone near the Israeli- Gaza border, hospital officials said, adding they believe he may have been mentally handicapped.

Of the 76 wounded, 16 were in critical condition. Among the wounded was Ibrahim Al-Atla, 25, a cameraman for the Palestine Broadcasting Corp., who was hit in the back with shrapnel, said Dr. Juma Al Saqqa, a Shifa Hospital official.

Also Wednesday, Gaza militants fired 11 rockets into Israel, slightly wounding one person in the town of Sderot.

"This is a horrible situation, and we urge the international community to notice the continuing Israeli escalation in Gaza immediately," Palestinian lawmaker Saeb Erekat said. "I'm afraid these numbers are going to multiply if we continue to be the forgotten zone in this region."

During Israel's monthlong offensive on Gaza, ground forces have repeatedly raided Gaza, searching for militants and weapons as artillery pounded the area and aircraft carried out attacks.

Israel launched its offensive in Lebanon after Hezbollah guerrillas killed three soldiers and captured two on Israel's northern border on July 12.

Israel withdrew from the Gaza Strip last summer, pulling out its military bases and evacuating 21 settlements. At the time, Israeli leaders said they would respond fiercely to any attacks from Gaza.

Khader Habib, a leader of Islamic Jihad in Gaza, said his group would respond to Wednesday's deaths with rocket attacks and suicide bombings. "We will carry out our (suicide) operations against Israeli soldiers," he said.

Also Wednesday, several Israeli tanks and bulldozers crossed the border into Gaza's Abassan region near the southern town of Khan Younis, witnesses said.

Just before the force entered, an Israeli helicopter dropped leaflets warning residents to stay indoors because the army was carrying out an operation against militants firing rockets into Israel, witnesses said.

The Palestinian phone company said more than 1,000 residents of Khan Younis got recorded messages from Israel, warning them not to hide weapons or shield militants. The residents were apparently picked at random, phone company officials said.

Complete coverage of the Mideast Meltdown is available in FOXNews.com's Mideast Center.