Israeli soldiers have killed three Palestinian militants who infiltrated the Jewish settlement of Kfar Darom, in the southern Gaza Strip.
The Israeli incursion has entered its second week
A Thai labourer was fatally wounded as the army and militants exchanged fire.
Israeli tanks also shelled the north Gaza town of Beit Lahiya early on Wednesday, killing three Palestinians and injuring 10 children, medics said.
The violence comes on the eighth day of Israel's military incursion into the northern Gaza Strip.
More than 75 Palestinians have been killed during the operation, which the Israelis say is aimed at ending rocket attacks by Palestinian militants on nearby Israeli towns.
Israeli army chief Moshe Yaalon warned that the operation, codenamed Days of Penitence, would last "as long as it takes" and could go on for weeks.
Late on Wednesday, Israeli helicopters fired missiles at targets near Gaza City, witnesses said.
There were no reports of casualties in the raid, on a metal workshop in the town of Jabaliya.
Medics said the shelling of Beit Lahiya killed a 15-year-old Palestinian in one house and two men in another.
A shell also struck a house where a Palestinian family was sleeping, wounding 10 children all aged under 12, hospital officials said.
Israeli military sources said the tanks fired at gunmen who had launched an anti-tank rocket from a house.
The BBC's Alan Johnston in Gaza said Tuesday had been the quietest day there since Israel's operation began a week ago.
But two late Israeli missile strikes rocked the territory.
The first hit a car in Gaza City, killing two Islamic Jihad militants, including senior member Bashir al-Dabbash.
He was one of the most senior militants killed in Gaza since Hamas leader Abdel-Aziz al-Rantissi was assassinated in April.
Islamic Jihad vowed revenge.
About 15,000 people in the area have been without water and electricity for days.
United Nations Secretary-General Kofi Annan has called on both Israel and the Palestinian Authority to show restraint.
US Secretary of State Colin Powell has urged Israeli Prime Minister Ariel Sharon to ensure that Israeli action was not excessive.
"I hope that whatever he does is proportionate to the threat that Israel is facing and I hope that this operation can come to a conclusion quickly," said Mr Powell.