RAMALLAH, West Bank ? Israel is fighting a war of survival and will “smash” Palestinian terror groups in an uncompromising military offensive, Israel’s prime minister on Sunday told a nation rattled by five suicide bombings in five days, including two attacks that killed 15 Israelis just hours earlier.

In a sign that Israel’s “Operation Protective Wall” was expanding, dozens of Israeli tanks entered the West Bank town of Qalqiliya late Sunday, Palestinian governor Mustafa Malki said. Armored vehicles also amassed near biblical Bethlehem. The Israeli military spokesman’s office said it would not give details of operational activities.

In the West Bank town of Ramallah, under Israeli control for the past three days, dozens of European peace activists, their arms raised and holding white flags, marched past bewildered Israeli soldiers into Yasser Arafat’s office to protest the confinement of the Palestinian leader by Israel. The protesters said they would stay with Arafat, who has accused Israel of trying to kill him, as a human shield.

Late Sunday, Israeli forces stormed a building where Palestinian gunmen were thought to be hiding, killing five, according to a Palestinian inside. Israel Radio said one of the five had an explosives belt. The Israeli military had no immediate comment.

Earlier in the day, Israeli forces surrounding Arafat’s building exchanged fire with his guards, and Palestinian officials said Arafat was just a few meters from the fighting. Several guards were wounded, two of them seriously.

The Israeli army spokesman, Brig. Gen. Ron Kitrey, acknowledged that Arafat was at risk, even if he was not a target.

Addressing the nation in a five-minute televised speech, Sharon said Israel is fighting a “war over our home,” and branded Arafat an enemy of the Jewish state and the “entire free world” as well as a danger to the Middle East.

“We must fight against this terrorism, fight with no compromise, pull up these wild plants by the roots, smash their infrastructure, because there is no compromise with terrorism,” Sharon said, adding that only then a cease-fire would be possible.

Palestinian Cabinet Minister Saeb Erekat said the speech was “void of substance, void of hope, void of realism.” Erekat said Sharon “slammed the door tonight in the face of all of those who are trying to de-escalate.”

In Israel, there were first signs of unease over the military campaign for which 20,000 reserve soldiers were mobilized, at a cost of millions of dollars a month. Key indicators suggested growing anxiety: the Tel Aviv Stock Exchange dropped by 5 percent points Sunday, and the dollar rose 2.8 percent against the shekel.

Some newspaper commentaries said the military campaign was mainly driven by Sharon’s need to settle a personal score with Arafat, who in 1982 was besieged by Sharon’s forces in Beirut, but was able to leave Lebanon with thousands of fighters.

“This explains Sharon’s tremendous urge to humiliate Arafat,” Nahum Barnea wrote in the Yediot Ahronot daily.

On the Israel-Lebanon border, Hezbollah guerrillas fired at an Israeli army base late Sunday, the second such incident in recent days, Israel radio stations reported, raising the possibility of a new front in the conflict. No one was hurt. The Israeli military had no comment.

Israelis’ nerves were rattled by two more suicide bombings Sunday, which brought to five the number of such attacks over five days. One blast went off in the port city of Haifa and the other in the Jewish settlement of Efrat in the West Bank.

In Haifa, a suicide bomber from the Islamic militant group Hamas blew himself up in a crowded restaurant, killing himself and 15 diners and wounding more than 40.

The blast was so powerful that it tore away much of the roof, and shattered tables and windows. Twisted piles of metal covered the floor, and wires dangled from what was left of the roof. “Even the moderately injured were on fire,” said a witness, Shimon Sabag, who helped administer first aid.

In Efrat, a suicide bomber walked into a paramedics’ dispatch station, blowing himself up near members of an intensive care crew. The attacker killed himself and wounded four medics, including a trainee who was in serious condition.

Israeli military commentators said Sunday’s explosions, which came less than two hours apart, were expected to accelerate Israel’s military campaign. The Cabinet met Sunday to review military plans.

Sharon’s pledge to press on with the offensive came despite a U.N. Security Council resolution calling on Israel to withdraw from Palestinian territory.

Israel’s ambassador to the United Nations said U.S. officials have suggested to Israel that it would not have to act immediately on the resolution because there’s no timeline. “Everyone is aware of this, including the Americans,” the ambassador, Yehuda Lancry, told Israel Army Radio.

In Ramallah, the Palestinians’ commercial center, Israeli troops tightened their control Sunday. Troops commandeered homes and buildings, set up sandbag emplacements draped with camouflage netting on residential streets, erected barricades and dug trenches, making the hilly streets into a near-impassable maze.

There were sporadic exchanges of fire. Reporters saw two bodies of Palestinians lying in a street in the center of the city, near 15 Palestinians kneeling against a wall under Israeli army guard. Soldiers moved house-to-house and in one case herded several handcuffed Palestinian policemen into a military vehicle.

Israel has been trying to isolate Arafat, confining him to a three-floor building in the sprawling government compound in Ramallah. However, Arafat has been giving interviews by mobile phone, and on Sunday, several dozen European peace activists marched into the compound, past Israeli troops.

The visitors hugged a smiling Arafat. A few left, but about 30 remained in the compound, saying they would serve as a human shield, including an Israeli-Canadian, Netta Golan, 30, who has been living in Ramallah for the past few months.

“I know that the only chance for Israelis to have peace and security is for the Palestinians to have peace and security,” Golan said in a telephone interview, adding that she and the others would not leave until the army withdraws.

Kitrey, the Israeli army spokesman, suggested that Israeli forces would try to tighten the isolation around Arafat, while keeping him relatively comfortable. “He won’t be hit. He will eat, drink, he will think about the situation and the deep hole he got himself and his people into,” Kitrey said.

Israel declared Ramallah a closed military zone and said foreigners, including journalists, would be removed. Although the army in the past had declared certain areas closed to the media, applying this to an entire city is a relatively new practice, and the threat to remove reporters was unusual. The Foreign Press Association in Israel issued a protest, saying that media must be allowed to cover a major story.

On Sunday afternoon, Anthony Shadid, a Washington-based Boston Globe reporter on assignment in Ramallah, was shot in the shoulder while standing in the doorway of a shop with Globe stringer Said al-Ghazali, said Globe foreign editor James F. Smith. Shadid was conscious and in stable condition in a private Arab hospital in Ramallah, Smith said. The bullet was lodged in the shoulder. It was not clear who shot him and the Israeli army was investigating.