Israel is preparing for a sizable military operation in the Gaza Strip, Israeli officials warned Thursday as rockets and mortar shells from the Hamas-ruled territory continued to pound southern Israel.

At least four Qassam rockets were fired at the Jewish state on Thursday, of which one damaged the fence of a kibbutz and the other two landed in open areas, local news service Ynet reported, adding that no injury was caused in the attacks.

Meanwhile, one of the several mortar shells launched against Israel hit the ceiling of the Erez border crossing, the gateway to and out of northern Gaza, causing damage but no injury, added the report.

The latest salvo followed a convulsive day when Gazan militants rained some 70 rockets and mortar shells upon southern Israel, causing no casualty but sending local residents to a widespread panic. A retaliatory Israeli airstrike killed a Hamas gunman in southern Gaza.

"We will not accept this situation... Whoever harms the citizens and soldiers of Israel will pay a heavy price," local daily The Jerusalem Post quoted Defense Minister Ehud Barak as saying.

Barak said he had ordered the Israeli army to be prepared to deliver a "response" to the cross-border violence.

In view of Wednesday's rocket rain, Israel's security cabinet convened an emergency meeting, during which a senior military officer briefed ministers on potential retaliatory moves that the defense establishment is mulling, local newspaper Ha'aretz reported.

Most strikes will be airborne and aimed at facilities believed to be of strategic importance to Hamas, said the officer, noting that current weather conditions are preventing the air force from launching the raids.

"We are not eager to strike, but we will not hesitate to act," an Israeli official was quoted as saying. "If Hamas is looking for noise, we will make Gaza very noisy."

While vowing to stage a harsh response to the artillery attacks, Israeli officials put a lid on the timing of the widely mentioned operation.

On Sunday, Prime Minister Ehud Olmert told the security cabinet that Israel would not give Hamas a "promo" of when and how the Jewish state would respond.

On Thursday, Foreign Minister Tzipi Livni met in Cairo with Egyptian President Hosni Mubarak, whose government brokered a truce deal between Israel and Hamas in June, which both sides generally honored for about five months before clashes resumed.

"Enough is enough," she told a press conference following the meeting, during which she rejected a call for restraint made by Mubarak and reiterated Israel will act to halt the "unbearable" rocket attacks.

Brushing away speculations that Israel would probably not take large-scale military actions before the Feb. 10 general election, Livni said if Hamas thinks in this way, "then it's wrong."

With his top diplomat warning that Israel is running out of patience with Hamas, Olmert on Thursday called directly on Gazan residents to stop Hamas, which he said was the common enemy of both Israelis and Gazans, from firing at Israel.

In this rare appeal he made during an interview with the Arab satellite station al-Arabiya, Olmert added his nation did not want to use its military force, but would not hesitate to use it against Hamas and Islamic Jihad, another Palestinian movement that claimed responsibility for many of recent rocket attacks.

As political leaders are ratcheting up their rhetoric against Gazan militants, Israeli rescue service has put ambulance staff in southern Israel on the highest alert.

(Xinhua News Agency December 26, 2008)