Four Israeli navy commandos were hurt in clashes during the brief incursion early Sunday to destroy a rocket launching site in northern Gaza, the Israeli military said. It said the troops later returned to Israeli territory.

Hamas said its fighters had fired at the Israeli force offshore and confirmed that they prevented it from landing, Reuters reported.

It was the first time that Israeli ground troops are known to have entered Gaza in the current offensive. But the operation was carried out by special forces and did not appear to be the beginning of a broad ground offensive.

Israeli airstrikes pounded targets in Gaza, with one hitting a center for the disabled and killing two patients and wounding four Palestinians. In a second attack Saturday night, an Israeli warplane flattened the home of Gaza police chief Taysir al-Batsh and damaged a nearby mosque as evening prayers ended, killing at least 18 people and wounding 50, officials said.

Israel has carried out more than 1,200 air strikes over the six-day offensive to try to diminish Hamas' ability to fire rockets at Israel. Hamas has fired nearly 700 rockets and mortars at Israel this week.

Critics say Israel's heavy bombardment of one of the most densely populated territories in the world is itself the main factor putting civilians at risk. More than 156 Palestinians have been killed so far.

NTJ/HH