Israeli forces killed six gunmen from the Hamas militant group in clashes in the northern part of the Gaza Strip on Saturday, amid worsening violence in the territory in recent days, Palestinian security sources said.
Security sources said four of the militants were killed when an Israeli rocket hit a house.
At least 11 other Palestinians were injured, mostly militants.
A column of Israeli tanks backed by attack helicopters moved deep into an area east of the town of Jabalya, just outside Gaza City.
Militants responded with anti-tank fire.
Earlier, an Israeli air strike destroyed a house in the southern Gaza town of Rafah, witnesses and medics said.
Israeli forces on Friday killed four Palestinians, three of them Hamas militants, in the biggest upsurge of Israeli-Palestinian violence in the Gaza Strip in weeks, residents said.
Almost 250 Palestinians, about half of them civilians, have been killed since Israel launched its offensive in Gaza in June to try to recover a captured soldier and stop cross-border rocket fire.
Hamas controls the Palestinian government and resumed rocket attacks on Israel earlier this week.
Israeli media reported that Defence Minister Amir Peretz had instructed the military to continue expanding its operations in Gaza to prevent rocket attacks on towns in southern Israel.
Peretz is originally from the town of Sderot, just outside Gaza, which has been hit frequently by rockets fired from Gaza over the past six months.