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

The violence came as Israel was embroiled in another, more publicized battle, on its northern border with Hezbollah guerrillas in Lebanon.

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

On Wednesday, Israel 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.

Most of those killed Wednesday were hit by tank fire, air strikes and in clashes with Israeli troops in fighting in eastern Gaza City. Another militant was killed in northern Gaza by an artillery shell. Dozens more were wounded. No Israel soldiers were hurt in the fighting.

Sixteen of the Palestinians killed were identified as militants by their respective militant groups. A three-year-old girl and two other men were also killed in the clash, hospital officials said. It was not clear if the two men were militants.

In a separate incident in northern Gaza, a five-year-old girl and her eight-month-old sister where killed when an artillery shell landed on their house, hospital officials said. Their mother, who was critically wounded, died later.

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

The army said it was checking both reports.

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

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

"This is a horrible situation, and we urge the international community to notice the continuing Israeli escalation in Gaza immediately,'' Palestinian legislator 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, Israeli ground forces repeatedly raided Gaza, searching for militants and weapons as artillery pounded the area and aircraft carry out attacks.

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

Khader Habib, a leader of Islamic Jihad in Gaza, said his group would respond to the latest 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 into the 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 cells firing rockets into Israel, witnesses said.

In a new tactic, aircraft also blasted several houses of Hamas and Islamic Jihad activists after warning people to leave. Homeowners said they received phone calls from people speaking broken Arabic and telling them to get out.

In an air strike late Wednesday missiles hit the house of a senior Hamas field commander Jihad Kahlout in the Jabaliya refugee camp, wounding four people in neighbouring houses and blowing out windows in a nearby hospital, officials said. The house was empty after the family received a call from the army Tuesday.

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