Israeli marines clashed with Hamas gunmen in the first reported ground incursion in the Gaza Strip, after the deadliest night of violence in Israel's latest offensive in which 18 members of the same family were killed.
The Israeli army said at least four soldiers were "lightly injured" on Sunday, as they attacked a site in northern Gaza the army said was being used to launch long-range rockets.
"During the mission a gunfight broke out, started by some terrorists operating at the site, during which four Israeli soldiers were lightly wounded," said the spokesman who declined to give further details on the operation.
The Qassam Brigades, Hamas' armed-wing, confirmed the exchange of gunfire "between our fighters and soldiers of the Zionist navy which tried to penetrate the zone of Sudanyia" in northwest Gaza.
Hamas said its fighters had fired at the Israeli force offshore, preventing them from landing.
Israel later dropped leaflets on northern Gaza urging residents to leave the area, ahead of an expected wider attack on the area.
The early morning incursion followed the deadliest night of Israeli bombing since it launched its campaign on Tuesday. A total of 52 Palestinians were reported killed overnight, bringing the toll to 166 in six days of attacks.
Eighteen people, from the same extended family, were killed in the deadliest attack since the bombardment of the Palestinian enclave began on Tuesday, when Israeli forces targeted the home of Gaza police chief Tayseer al-Batsh in the Toufah area of Gaza City.
Ashraf al-Qedra, a spokesman for the Gaza health ministry, told Al Jazeera that the house, located near a mosque in Tofah, was hit after Ramadan prayers.
"It’s a new massacre being committed against our people in Gaza strip. People were trying to get out of the mosque after they finished night time 'Taraweh' prayers but suddenly they saw the house under intensive shelling.”
Batsh was among the wounded, Palestinian officials told the AFP news agency.
Israel says its bombardment is to end rocket fire by Palestinian fighters into Israeli cities. The UN on Saturday said that three quarters of those killed in Gaza were civilians.
The Israeli army said late on Saturday that rockets fired from Gaza had hit the cities of Hebron and Bethlehem. No deaths or injuries was reported.
|INTERACTIVE: Gaza Under Attack
Palestinians in the cities rioted against Israeli troops on Sunday morning.
More than 500 missiles have struck Israel during the conflict, but none have resulted in Israeli deaths. More than 1,200 Israeli attacks have been reported since Tuesday.
An Israeli air raid on Saturday hit a centre for the disabled in Gaza, killing three patients and a nurse.
The UN Security Council called for a cessation of hostilities and top diplomats from the UK, France, Germany and the US are due to meet later on Sunday to discuss the need for a ceasefire.