A rocket fired from Gaza exploded in a shopping center in this southern Israeli city Wednesday, wounding at least 14 people, as President Bush wrapped up talks in Jerusalem with Israel's prime minister.

The attack raised the chances that Israel will send large numbers of ground forces into the Hamas-ruled Gaza Strip - something the army chief has reportedly decided he wants to do.

The rocket ripped through the roof of a mall in Ashkelon, causing a large chunk of the ceiling to collapse in a huge pile of rubble and twisted metal. Four windows were blown out of the side of the building.

After his talks with Bush, Prime Minister Ehud Olmert said Israel will take the "necessary steps" to stop violence from Gaza and called the Ashkelon attack "intolerable and unacceptable."

"The government of Israel is committed to stop it," said at a world conference marking Israel's 60th anniversary.

Prior to the attack, Olmert had told Bush that his government was hoping it would "not have to act against Hamas in other ways with the military power that Israel hasn't yet started to use in a serious manner in order to stop it."

Liron Azulai, 26, an electronics student, was in the shopping center when the rocket struck. "The whole ceiling fell on me," he said while awaiting treatment at the hospital. He said Israel must act to stop the rocket attacks. "You cannot live like this," he said. "It's very frightening."

The Magen David Adom rescue service said 14 people were wounded. It said all the injured had been evacuated, including four people who were briefly trapped under the rubble.

Leah Malul of Barzilai Hospital in Ashkelon said two women and two children were seriously wounded.

Two militant groups, the Iranian-backed Islamic Jihad and the Hamas-linked Popular Resistance Committees, claimed responsibility. Earlier Wednesday, five Palestinians were killed in Israeli military operations in Gaza.

While militants have fired homemade rockets into rural southern Israeli border towns for several years, only recently have they gained the capability to target Ashkelon, a city of 110,000 about nine miles from the Gaza border. The longer-range attacks involve foreign-made Grad-type rockets.

Israel believes Islamic Jihad is getting the Grads from Iran. "It's part of the Iranian war against Israel," Former Deputy Defense Minister Ephraim Sneh told Israel Radio.

Casualties have mounted recently from daily rocket attacks by Palestinian militants on Israel. Two people were killed in the last week. Israel has so far resisted a broad offensive, fearing heavy casualties to its soldiers.

Even before the latest hit, the Israeli military commander, Lt. Gen. Gabi Ashkenazi, changed his stand and came out in favor of a ground offensive, defense officials said. They spoke on condition of anonymity because they were not at liberty to disclose policy considerations.

Israel's high-tech military has been unable to find a way to stop the crude rockets. Past invasions have halted daily rocket fire only briefly, and the barrages resumed as soon as Israeli troops pulled out.

Egypt has been working to mediate a truce between Israel and Hamas. In a rare hint that Israel might accept it, Olmert referred to "possible terms in what may emerge as a cease-fire" in his talks with a high-level Egyptian mediator.

Before he leaves office, Bush hopes to broker a peace agreement between Israel and the moderate Palestinian government of President Mahmoud Abbas in the West Bank.

Israel has warned it will not carry out any peace agreement until Abbas regains control of Gaza. Hamas seized control of Gaza last June from Abbas' troops.

Abbas claims the West Bank and Gaza - areas located on opposite sides of Israel - for a future independent state. Hamas, an Islamic militant group committed to Israel's destruction, opposes the peace talks.