Israel has widened a major, two-week operation in northern Gaza by thrusting deeper into the town of Beit Lahiya.
The Israeli operation entered its third week on Tuesday
The Israeli commander in Gaza said his troops met significant resistance from homemade bombs and anti-tank rockets.
A member of Hamas militant movement was killed and two others were wounded by an Israeli missile fired at the town.
The operation is the deadliest in Gaza since the start of the Palestinian uprising four years ago and has left more than 100 Palestinians dead.
An Israeli helicopter gunship fired a missile near a house during the fighting in Beit Lahiya, killing 22-year-old member of Hamas's armed wing Mohammed Marouf, Palestinian medics said.
Meanwhile, an 11-year-old Palestinian schoolgirl, Ghadir Mokheimer, who was hit by Israeli army gunfire at her school in Gaza's Khan Younis refugee camp on Tuesday has died of her injuries.
Codenamed Days of Penitence, Israel said the north Gaza operation was launched to wipe out the threat of homemade rockets being fired by Hamas at Sderot, an Israeli town just beyond the north-east borders of Gaza.
Two young boys were killed by one such rocket after the operation began, triggering a massive Israeli escalation.
One Israeli soldier has been killed and 13 wounded during the operation.
About 40% of Palestinians killed in fighting - which until now has been centred on the crowded Jabaliya refugee camp - are reported to be civilians.
Israeli officials say a custom-built radar system in Sderot has passed its first live test, giving residents a 20-second warning of an incoming rocket attack.
"The alert was heard throughout the town, and residents took
shelter in time. The system is a success," a municipal security officer told the Reuters news agency.
The rockets landed in open fields nearby without causing any injuries.
Hamas in Gaza has insisted that it cannot be crushed by Israeli forces and defended its targeting of civilians in rocket attacks as a legitimate response to what it called Israel's aggression.
"For two weeks, the Zionist enemy has not achieved its goals," spokesman Musher Masri told the AFP news agency.
"We are defending the killing of women and children and the bulldozing of land and homes. It is natural for any Palestinian to react to any such aggression," said Mr Masri, whose brother was among the militants killed in Gaza in the operation.
Qawasma was forced to strip to show he was not armed
In the West Bank, a senior Hamas military leader was arrested in Hebron.
Israeli soldiers surrounded a building and ordered Imad Qawasma to come out, forcing him to strip to his underwear to show he was not armed.
Moments later, Israeli bulldozers began demolishing the structure, witnesses said.
The Hebron branch of Hamas claimed responsibility for a double suicide bombing in Beersheba, southern Israel on 31 August in which 16 Israelis were killed.