Israel's offensive on Thursday triggered the armed wing of Hamas to respond by firing six makeshift rockets into Israel. No one was wounded. The rockets were the first fired by Hamas in more than a month; but other armed groups have kept up such attacks.
Later on Thursday, an Israeli missile fired from an unmanned drone killed two Palestinians including a girl and wounded more than 10 others in the Shijaia neighbourhood in Gaza City, local residents and hospital staff said.
An Israeli army spokesman confirmed the attack was aimed at a senior member from the armed wing of Hamas, the Izz al-Din al-Qassam Brigades, named Ashraf Ferwana but local residents said Ferwana survived, although his brother was killed.
Overnight, Israeli troops backed by helicopter gunships entered the southern Gaza village of Absan under cover of darkness, touching off clashes.
At least three Hamas members were killed along with two bystanders, a man and his teenage son.
Relatives of a Palestinian
teenager after he was killed
The sixth dead was a Hamas member, but he was not carrying weapons at the time, residents said.
The Israeli army confirmed its forces were operating in the area, saying they were looking for facilities used by armed groups waging a six-year-old Palestinian uprising against the Israeli occupation. Troops fired on gunmen who tried to attack them, an army spokesman said.
"This is an area believed to conceal tunnels and other forms of infrastructure used by terrorist groups," he said.