JERUSALEM  With its punishing air attacks on Gaza about to enter a fifth day, its gunboats gathering near the Gaza port and its ground forces poised for imminent action, Israel said Tuesday that it was considering a 48-hour cease-fire that would also require Hamas to stop its rocket fire.

The idea was in an early stage, a result of a conversation between Foreign Minister Bernard Kouchner of France and Defense Minister Ehud Barak of Israel seeking at least a temporary pause in the fighting that would allow humanitarian relief to be delivered to the besieged coastal strip. Aides to Mr. Barak said he was interested in exploring it and would do so with Prime Minister Ehud Olmert and the rest of the cabinet on Wednesday.

“The leading option right now is still a ground invasion, but the target of this operation is an improved cease-fire, and if that can come without the invasion, fine,” said a close aide to Mr. Barak, speaking on the condition of anonymity because he is not Mr. Barak’s authorized spokesman. “But, of course, Hamas has to agree, and there has to be a mechanism to make it work.”

In Paris, where Mr. Kouchner was meeting with his European Union colleagues over the Gaza crisis, he called publicly for a permanent cease-fire. A similar call came from the so-called quartet of powers focused on the region  the United Nations, the European Union, the United States and Russia.

President Bush and Secretary of State Condoleezza Rice made phone calls to Israeli and Arab leaders to explore prospects for halting the fighting. They emphasized that any cease-fire should be “durable and sustainable,” compelling Hamas to end its rocket attacks, a State Department spokesman said.

“That is different from the cease-fire that existed in the last six months,” said the spokesman, Gordon Duguid, noting that Hamas had routinely violated the previous agreement by firing rockets into southern Israel.

Image Credit... The New York Times

The flurry of diplomacy appeared to be mostly byplay in Jerusalem and Gaza, as Israeli officials spoke of a continuing and expanding military operation, and Hamas vowed to step up its resistance. Israeli warplanes attacked tunnels used to smuggle supplies in southern Gaza and destroyed the home of a top militant leader.

Mr. Olmert told the Israeli president, Shimon Peres, that the airstrikes were the first of several planned phases, according to spokesmen for the officials. It was also clear that the number of targets available from the air was declining, making the likelihood of a ground offensive greater.

In Gaza, Hamas militants issued a taped statement vowing revenge for those killed in the Israeli air raids since Saturday and warning that a ground invasion would prove painful for Israel. Palestinian officials say that more than 370 people have been killed, among them, the United Nations says, at least 62 women and children and an unknown number of civilian men. Two sisters, ages 4 and 11, were killed in a strike in the north as concern was growing around the world that the assault was taking a terrible toll on civilians.

“It would be easier to dry the sea of Gaza than to defeat the resistance and uproot Hamas, which is in every house of Gaza,” said the statement from the military wing of Hamas. It was played on Hamas’s television station, which had been shut down by an Israeli missile but went back on the air by broadcasting from a mobile van. The statement added that if there was a ground invasion, “the children of Gaza will be collecting the body parts of your soldiers and the ruins of tanks.”

Hamas continued to fire longer-range rockets at Israel, shooting deep into the city of Ashdod for a second day as well as into Beersheba, a major city in Israel’s south, where one landed in an empty kindergarten classroom. There was a report of light injuries as well as a number of people in shock.

Israeli warplanes, returning repeatedly to the same section of Gaza City overnight, pummeled the main government complex with about 20 missiles, residents said Tuesday. The building had been evacuated since the start of the operation on Saturday, which also hit nearly all of Hamas’s security complexes, its university and other symbols of its sovereignty and power.

The Nakhala family, which lives next to the compound, was inspecting the damage on Tuesday morning and recounting the utter fear and panic they all felt as the missiles hit.

“We have no shelters in Gaza,” said the father, Osama Nakhala. “Where shall we go? I also have to worry about my mother, who is 80 years old and paralyzed.”